Systems and processes for polyacrylic acid production

ABSTRACT

Disclosed are systems and methods for the production of polyacrylic acid and superabsorbent polymers from ethylene oxidation to form ethylene oxide. Reacting the ethylene oxide with carbon monoxide to form to beta propiolactone (BPL) or polypropiolactone (PPL), or a combination thereof. An outlet configured to provide a carbonylation stream comprising the BPL or PPL, or a combination thereof and using one or more reactors to convert BPL to acrylic acid or to convert at least some of the BPL to PPL, and then to convert PPL to acrylic acid. An outlet configured to provide a PPL stream to a second reactor tm to convert at least some of the PPL to AA or a third reactor to convert at least some of the PPL to AA. The outlet configured to provide an AA stream to a fourth reactor to convert the AA to polyacrylic acid.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a U.S. national phase patent application ofPCT/US2016/017844, filed Feb. 12, 2016, which claims priority to and thebenefit of U.S. Provisional Patent Application No. 62/116,229, filedFeb. 13, 2015, each of which is incorporated herein by reference in itsentirety.

FIELD

The present disclosure relates generally to the production ofpolyacrylic acid, and more specifically to the production of polyacrylicacid from ethylene.

BACKGROUND

Methods have been described where acrylic acid (AA) is produced via thepyrolysis of polypropiolactone (PPL) (e.g., see U.S. Pat. No.2,361,036). However, PPL pyrolysis as described in this and relatedliterature does not produce acrylic acid of sufficient purity for directuse in radical polymerization for superabsorbent polymer (SAP)production. Instead, the methods require expensive and energy intensivepurification of the acrylic acid before it can be polymerized to produceSAP. There is therefore a need in the art for methods of directlyproducing glacial acrylic without the need for expensive and energyintensive AA purification.

Glacial acrylic acid, a purified form of acrylic acid, can be used tomake polyacrylic acid for superabsorbent polymers (SAPs). At least twoproblems currently known in the art hamper the production and/orpurification of glacial acrylic acid.

First, acrylic acid is primarily produced via vapor phase oxidation ofpropylene via an acrolein aldehyde intermediate. Products of propyleneoxidation, such as the acrolein aldehyde, and by-products of propyleneoxidation, such as other aldehyde impurities, are difficult andexpensive to remove from crude acrylic acid. Aldehyde impurities hinderpolymerization to polyacrylic acid and discolor this polymer.

Second, acrylic acid is extremely reactive and susceptible to unwantedMichael addition and free-radical polymerization with itself. Therefore,even after glacial acrylic acid is purified, it gradually degradesunless stabilizers, such as radical polymerization inhibitors, are addedto retard unwanted side reactions. Stabilizers, however, are expensiveand may interfere with the conversion of acrylic acid to polyacrylicacid.

Thus, there is a need in the art for methods to produce acrylic acid,including glacial acrylic acid, on a commercial scale.

BRIEF SUMMARY

The systems and processes described herein directly produce acrylic acid(including glacial acrylic acid), and provide solutions to problemsknown in the art related to the production of acrylic acid. Describedherein are systems and methods for producing polyacrylic acid (PAA) fromethylene, rather than propylene, that eliminate products and byproductsof propylene oxidation. Because the disclosed methods are conductedwithin the single integrated system described below, highly reactiveintermediates, including ethylene oxide (EO), beta propiolactone (BPL),and acrylic acid (AA) are swiftly carried through to the relativelystable polyacrylic acid (PAA). The disclosed systems and methods can beused to efficiently prepare PAA and SAPs of excellent purity.

Also described are systems and methods for the production of polyacrylicacid and superabsorbent polymers from ethylene. Further described aresystems and methods to prepare superabsorbent polymers from theethylene-derived polyacrylic acid.

In one aspect, a system is provided for the production of polyacrylicacid (PAA) from ethylene, within an integrated system, comprising:

-   -   an oxidative reactor, comprising an inlet fed by ethylene, an        oxidative reaction zone that converts at least some of the        ethylene to ethylene oxide (EO), and an outlet which provides an        outlet stream comprising the EO,    -   a central reactor, comprising an inlet fed by an EO source, and        a carbon monoxide (CO) source, a central reaction zone that        converts at least some of the EO to beta propiolactone (BPL) or        polypropiolactone (PPL), and an outlet which provides an outlet        stream comprising the BPL or PPL,    -   one or more of (i), (ii) and (iii):        -   (i) a first reactor, comprising an inlet fed by the outlet            stream comprising BPL of the central reactor, a first            reaction zone that converts at least some of the BPL to AA,            and an outlet which provides an outlet stream comprising the            AA,        -   (ii) a second (a) reactor, comprising an inlet fed by the            outlet stream comprising BPL of the central reactor, a            second (a) reaction zone that converts at least some of the            BPL to PPL, and an outlet which provides an outlet stream            comprising the PPL, and a second (b) reactor, comprising an            inlet fed by the outlet stream comprising PPL of the            second (a) reactor, a second (b) reaction zone that converts            at least some of the PPL to AA, and an outlet which provides            an outlet stream comprising the AA, and        -   (iii) a third reactor, comprising an inlet fed by the outlet            stream comprising PPL of the central reactor, a third            reaction zone that converts at least some of the PPL to a            third product, and an outlet which provides an outlet stream            comprising the AA, and        -   (iv) a fourth reactor, comprising an inlet fed by the outlet            stream comprising AA of one or more of the first, second (b)            and third reactor, a fourth reaction zone that converts at            least some of the AA to polyacrylic acid (PAA), or a salt            thereof, and an outlet which provides an outlet stream            comprising the PAA, or a salt thereof, and    -   a controller for independently modulating production of the EO,        BPL, PPL, AA and PAA.

In one variation, provided is an integrated system for producingpolyacrylic acid (PAA) from ethylene, comprising:

-   -   an oxidative reactor, comprising:        -   an inlet configured to receive ethylene,        -   an oxidative reaction zone configured to convert at least            some of the ethylene to ethylene oxide (EO), and        -   an outlet configured to provide an EO stream comprising the            EO;    -   a central reactor, comprising:        -   an inlet configured to receive EO from the EO stream of the            oxidative reactor, and carbon monoxide (CO) from a CO            source,        -   a central reaction zone configured to convert at least some            of the EO to beta propiolactone (BPL) or polypropiolactone            (PPL), or a combination thereof, and        -   an outlet configured to provide a carbonylation stream            comprising the BPL, or a carbonylation stream comprising the            PPL, or a combination thereof;    -   one or more of (i), (ii) and (iii):        -   (i) a first reactor, comprising:            -   an inlet configured to receive BPL from the                carbonylation stream of the central reactor,            -   a first reaction zone configured to convert at least                some of the BPL to AA, and            -   an outlet configured to provide an AA stream comprising                the AA,        -   (ii) a second (a) reactor, comprising:            -   an inlet configured to receive BPL from the                carbonylation stream of the central reactor,            -   a second (a) reaction zone configured to convert at                least some of the BPL to PPL, and            -   an outlet configured to provide a PPL stream comprising                the PPL, and        -   a second (b) reactor, comprising:            -   an inlet configured to receive the PPL stream of the                second (a) reactor,            -   a second (b) reaction zone configured to convert at                least some of the PPL to AA, and            -   an outlet configured to provide an AA stream comprising                the AA, and        -   (iii) a third reactor, comprising:            -   an inlet configured to receive PPL from the                carbonylation stream of the central reactor,            -   a third reaction zone configured to convert at least                some of the PPL to AA, and            -   an outlet configured to provide an AA stream comprising                the AA;    -   a fourth reactor, comprising:        -   an inlet configured to receive the AA stream of one or more            of the first, second (b) and third reactor,        -   a fourth reaction zone configured to convert at least some            of the AA to polyacrylic acid (PAA), or a salt thereof, and        -   an outlet configured to provide a PAA stream comprising the            PAA, or a salt thereof; and    -   a controller to independently modulate production of the EO,        BPL, PPL, AA and PAA.

In certain embodiments, the system further comprises a SAP reactorconfigured to receive the PAA stream, and to convert at least some ofthe PAA in the PAA stream to a SAP.

In some aspects, provided is a method for converting ethylene topolyacrylic acid (PAA) within an integrated system, the methodcomprising:

providing an ethylene stream comprising ethylene to an oxidative reactorof the integrated system;

converting at least a portion of the ethylene in the ethylene stream toethylene oxide (EO) in the oxidative reactor to produce an EO streamcomprising the EO;

providing the EO stream from the oxidative reactor, and a carbonmonoxide (CO) stream comprising CO to a central reaction zone of theintegrated system;

contacting the EO stream and the CO stream with a metal carbonyl in thecentral reaction zone;

converting at least a portion of the EO in the EO stream to betapropiolactone (BPL) or polypropiolactone (PPL), or a combinationthereof, in the central reaction zone to produce a carbonylation streamcomprising BPL, or a carbonylation stream comprising PPL, or acombination thereof;

(i) directing the carbonylation stream comprising BPL to an AA reactor,and converting at least some of the BPL in the carbonylation stream toAA in the AA reactor to produce an AA stream comprising the AA; or

(ii) directing the carbonylation stream comprising BPL to a PPL reactor,converting at least some of the BPL in the carbonylation stream to PPLin the PPL reactor to produce a PPL stream comprising PPL, directing thePPL stream to an AA reactor (also referred to in FIG. 1 as second (b)reactor), and converting at least some of the PPL to AA in the AAreactor to produce an AA stream; or

(iii) directing the carbonylation stream comprising PPL to an AAreactor, and converting at least some of the PPL in the carbonylationstream to AA in the AA reactor to produce an AA stream comprising AA; or

any combinations of (i)-(iii) above;

directing the AA streams of (i)-(iii) above to a PAA reactor; and

converting at least a portion of the AA of the AA streams of (i)-(iii)above to polyacrylic acid (PAA), or a salt thereof, in the PAA reactor.

In another aspect, related methods are disclosed for the production ofSAPs and PAA from ethylene.

Provided in another aspect is an article, such as a disposable diaper,comprising any of the SAPs described herein. The disclosed systems,methods and articles are described in greater detail below.

BRIEF DESCRIPTION OF THE FIGURES

The present application can be best understood by reference to thefollowing description taken in conjunction with the accompanying FIGURE,in which like parts may be referred to by like numerals.

FIG. 1 shows, in one embodiment, an exemplary process schematic for thedisclosed methods and systems.

DEFINITIONS

Definitions of specific functional groups and chemical terms aredescribed in more detail below. The chemical elements are identified inaccordance with the Periodic Table of the Elements, CAS version,Handbook of Chemistry and Physics, 75^(th) Ed., inside cover, andspecific functional groups are generally defined as described therein.Additionally, general principles of organic chemistry, as well asspecific functional moieties and reactivity, are described in OrganicChemistry, Thomas Sorrell, University Science Books, Sausalito, 1999;Smith and March March's Advanced Organic Chemistry, 5^(th) Edition, JohnWiley & Sons, Inc., New York, 2001; Larock, Comprehensive OrganicTransformations, VCH Publishers, Inc., New York, 1989; Carruthers, SomeModern Methods of Organic Synthesis, 3^(rd) Edition, CambridgeUniversity Press, Cambridge, 1987.

The terms “halo” and “halogen” as used herein refer to an atom selectedfrom fluorine (fluoro, —F), chlorine (chloro, —Cl), bromine (bromo,—Br), and iodine (iodo, —I).

The term “aliphatic” or “aliphatic group”, as used herein, denotes ahydrocarbon moiety that may be straight-chain (i.e., unbranched),branched, or cyclic (including fused, bridging, and spiro-fusedpolycyclic) and may be completely saturated or may contain one or moreunits of unsaturation, but which is not aromatic. In some variations,the aliphatic group is unbranched or branched. In other variations, thealiphatic group is cyclic. Unless otherwise specified, in somevariations, aliphatic groups contain 1-30 carbon atoms. In certainembodiments, aliphatic groups contain 1-12 carbon atoms. In certainembodiments, aliphatic groups contain 1-8 carbon atoms. In certainembodiments, aliphatic groups contain 1-6 carbon atoms. In certainembodiments, aliphatic groups contain 1-5 carbon atoms, In certainembodiments, aliphatic groups contain 1-4 carbon atoms, in yet otherembodiments aliphatic groups contain 1-3 carbon atoms, and in yet otherembodiments aliphatic groups contain 1-2 carbon atoms. Suitablealiphatic groups include, for example, linear or branched, alkyl,alkenyl, and alkynyl groups, and hybrids thereof such as(cycloalkyl)alkyl, (cycloalkenyl)alkyl or (cycloalkyl)alkenyl.

The term “heteroaliphatic” as used herein, refers to aliphatic groupswherein one or more carbon atoms are independently replaced by one ormore atoms selected from the group consisting of oxygen, sulfur,nitrogen, phosphorus, or boron. In certain embodiments, one or twocarbon atoms are independently replaced by one or more of oxygen,sulfur, nitrogen, or phosphorus. Heteroaliphatic groups may besubstituted or unsubstituted, branched or unbranched, cyclic or acyclic,and include “heterocycle,” “hetercyclyl,” “heterocycloaliphatic,” or“heterocyclic” groups. In some variations, the heteroaliphatic group isbranched or unbranched. In other variations, the heteroaliphatic groupis cyclic. In yet other variations, the heteroaliphatic group isacyclic.

The term “unsaturated”, as used herein, means that a moiety has one ormore double or triple bonds.

The terms “cycloaliphatic”, “carbocycle”, or “carbocyclic”, used aloneor as part of a larger moiety, refer to a saturated or partiallyunsaturated cyclic aliphatic monocyclic, bicyclic, or polycyclic ringsystems, as described herein, having from 3 to 12 members, wherein thealiphatic ring system is optionally substituted as defined above anddescribed herein. Cycloaliphatic groups include, for example,cyclopropyl, cyclobutyl, cyclopentyl, cyclopentenyl, cyclohexyl,cyclohexenyl, cycloheptyl, cycloheptenyl, cyclooctyl, cyclooctenyl, andcyclooctadienyl. In certain embodiments, the cycloalkyl has 3-6 carbons.The terms “cycloaliphatic”, “carbocycle” or “carbocyclic” also includealiphatic rings that are fused to one or more aromatic or nonaromaticrings, such as decahydronaphthyl or tetrahydronaphthyl, where theradical or point of attachment is on the aliphatic ring. In certainembodiments, a carbocyclic group is bicyclic. In certain embodiments, acarbocyclic group is tricyclic. In certain embodiments, a carbocyclicgroup is polycyclic.

The term “alkyl,” as used herein, refers to a saturated hydrocarbonradical. In some variations, the alkyl group is a saturated, straight-or branched-chain hydrocarbon radicals derived from an aliphatic moietycontaining between one and six carbon atoms by removal of a singlehydrogen atom. Unless otherwise specified, in some variations, alkylgroups contain 1-12 carbon atoms. In certain embodiments, alkyl groupscontain 1-8 carbon atoms. In certain embodiments, alkyl groups contain1-6 carbon atoms. In certain embodiments, alkyl groups contain 1-5carbon atoms, In certain embodiments, alkyl groups contain 1-4 carbonatoms, in yet other embodiments alkyl groups contain 1-3 carbon atoms,and in yet other embodiments alkyl groups contain 1-2 carbon atoms.Alkyl radicals may include, for example, methyl, ethyl, n-propyl,isopropyl, n-butyl, iso-butyl, sec-butyl, sec-pentyl, iso-pentyl,tert-butyl, n-pentyl, neopentyl, n-hexyl, sec-hexyl, n-heptyl, n-octyl,n-decyl, n-undecyl, and dodecyl.

The terms “alkene” and “alkenyl,” as used herein, denote a monovalentgroup having at least one carbon-carbon double bond. In some variations,the alkenyl group is a monovalent group derived from a straight- orbranched-chain aliphatic moiety having at least one carbon-carbon doublebond by the removal of a single hydrogen atom. Unless otherwisespecified, in some variations, alkenyl groups contain 2-12 carbon atoms.In certain embodiments, alkenyl groups contain 2-8 carbon atoms. Incertain embodiments, alkenyl groups contain 2-6 carbon atoms. In certainembodiments, alkenyl groups contain 2-5 carbon atoms, In certainembodiments, alkenyl groups contain 2-4 carbon atoms, in yet otherembodiments alkenyl groups contain 2-3 carbon atoms, and in yet otherembodiments alkenyl groups contain 2 carbon atoms. Alkenyl groupsinclude, for example, ethenyl, propenyl, butenyl, and1-methyl-2-buten-1-yl.

The term “alkynyl,” as used herein, refers to a monovalent group havingat least one carbon-carbon triple bond. In some variations, the alkynylgroup is a monovalent group derived from a straight- or branched-chainaliphatic moiety having at least one carbon-carbon triple bond by theremoval of a single hydrogen atom. Unless otherwise specified, in somevariations, alkynyl groups contain 2-12 carbon atoms. In certainembodiments, alkynyl groups contain 2-8 carbon atoms. In certainembodiments, alkynyl groups contain 2-6 carbon atoms. In certainembodiments, alkynyl groups contain 2-5 carbon atoms, In certainembodiments, alkynyl groups contain 2-4 carbon atoms, in yet otherembodiments alkynyl groups contain 2-3 carbon atoms, and in yet otherembodiments alkynyl groups contain 2 carbon atoms. Representativealkynyl groups include, for example, ethynyl, 2-propynyl (propargyl),and 1-propynyl.

The term “carbocycle” and “carbocyclic ring” as used herein, refers tomonocyclic and polycyclic moieties wherein the rings contain only carbonatoms. Unless otherwise specified, carbocycles may be saturated,partially unsaturated or aromatic, and contain 3 to 20 carbon atoms.Representative carbocyles include, for example, cyclopropane,cyclobutane, cyclopentane, cyclohexane, bicyclo[2,2,1]heptane,norbornene, phenyl, cyclohexene, naphthalene, and spiro[4.5]decane.

The term “aryl” used alone or as part of a larger moiety as in“aralkyl”, “aralkoxy”, or “aryloxyalkyl”, refers to monocyclic andpolycyclic ring systems having a total of five to 20 ring members,wherein at least one ring in the system is aromatic and wherein eachring in the system contains three to twelve ring members. The term“aryl” may be used interchangeably with the term “aryl ring”. In certainembodiments, “aryl” refers to an aromatic ring system which includes,for example, phenyl, naphthyl, and anthracyl, which may bear one or moresubstituents. Also included within the scope of the term “aryl”, as itis used herein, is a group in which an aromatic ring is fused to one ormore additional rings, such as benzofuranyl, indanyl, phthalimidyl,naphthimidyl, phenanthridinyl, and tetrahydronaphthyl.

The terms “heteroaryl” and “heteroar-”, used alone or as part of alarger moiety, e.g., “heteroaralkyl”, or “heteroaralkoxy”, refer togroups having 5 to 14 ring atoms, preferably 5, 6, 9 or 10 ring atoms;having 6, 10, or 14 pi (π) electrons shared in a cyclic array; andhaving, in addition to carbon atoms, from one to five heteroatoms. Theterm “heteroatom” refers to nitrogen, oxygen, or sulfur, and includesany oxidized form of nitrogen or sulfur, and any quaternized form of abasic nitrogen. Heteroaryl groups include, for example, thienyl,furanyl, pyrrolyl, imidazolyl, pyrazolyl, triazolyl, tetrazolyl,oxazolyl, isoxazolyl, oxadiazolyl, thiazolyl, isothiazolyl,thiadiazolyl, pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, indolizinyl,purinyl, naphthyridinyl, benzofuranyl and pteridinyl. The terms“heteroaryl” and “heteroar-” as used herein, also include groups inwhich a heteroaromatic ring is fused to one or more aryl,cycloaliphatic, or heterocyclyl rings, where the radical or point ofattachment is on the heteroaromatic ring. Examples include indolyl,isoindolyl, benzothienyl, benzofuranyl, dibenzofuranyl, indazolyl,benzimidazolyl, benzthiazolyl, quinolyl, isoquinolyl, cinnolinyl,phthalazinyl, quinazolinyl, quinoxalinyl, 4H-quinolizinyl, carbazolyl,acridinyl, phenazinyl, phenothiazinyl, phenoxazinyl,tetrahydroquinolinyl, tetrahydroisoquinolinyl, andpyrido[2,3-b]-1,4-oxazin-3(4H)-one. A heteroaryl group may be mono- orbicyclic. The term “heteroaryl” may be used interchangeably with theterms “heteroaryl ring”, “heteroaryl group”, or “heteroaromatic”, any ofwhich terms include rings that are optionally substituted. The term“heteroaralkyl” refers to an alkyl group substituted by a heteroaryl,wherein the alkyl and heteroaryl portions independently are optionallysubstituted.

As used herein, the terms “heterocycle”, “heterocyclyl”, “heterocyclicradical”, and “heterocyclic ring” are used interchangeably and may besaturated or partially unsaturated, and have, in addition to carbonatoms, one or more, preferably one to four, heteroatoms, as definedabove. In some variations, the heterocyclic group is a stable 5- to7-membered monocyclic or 7- to 14-membered bicyclic heterocyclic moietythat is either saturated or partially unsaturated, and having, inaddition to carbon atoms, one or more, preferably one to four,heteroatoms, as defined above. When used in reference to a ring atom ofa heterocycle, the term “nitrogen” includes a substituted nitrogen. Asan example, in a saturated or partially unsaturated ring having 0-3heteroatoms selected from oxygen, sulfur or nitrogen, the nitrogen maybe N (as in 3,4-dihydro-2H-pyrrolyl), NH (as in pyrrolidinyl), or ⁺NR(as in N-substituted pyrrolidinyl).

A heterocyclic ring can be attached to its pendant group at anyheteroatom or carbon atom that results in a stable structure and any ofthe ring atoms can be optionally substituted. Examples of such saturatedor partially unsaturated heterocyclic radicals include, for example,tetrahydrofuranyl, tetrahydrothienyl, pyrrolidinyl, pyrrolidonyl,piperidinyl, pyrrolinyl, tetrahydroquinolinyl, tetrahydroisoquinolinyl,decahydroquinolinyl, oxazolidinyl, piperazinyl, dioxanyl, dioxolanyl,diazepinyl, oxazepinyl, thiazepinyl, morpholinyl, and quinuclidinyl. Theterms “heterocycle”, “heterocyclyl”, “heterocyclyl ring”, “heterocyclicgroup”, “heterocyclic moiety”, and “heterocyclic radical”, are usedinterchangeably herein, and also include groups in which a heterocyclylring is fused to one or more aryl, heteroaryl, or cycloaliphatic rings,such as indolinyl, 3H-indolyl, chromanyl, phenanthridinyl, ortetrahydroquinolinyl, where the radical or point of attachment is on theheterocyclyl ring. A heterocyclyl group may be mono- or bicyclic. Theterm “heterocyclylalkyl” refers to an alkyl group substituted by aheterocyclyl, wherein the alkyl and heterocyclyl portions independentlyare optionally substituted.

As used herein, the term “partially unsaturated” refers to a ring moietythat includes at least one double or triple bond. The term “partiallyunsaturated” is intended to encompass rings having multiple sites ofunsaturation, but is not intended to include aryl or heteroarylmoieties, as herein defined.

As described herein, compounds described herein may contain “optionallysubstituted” moieties. In general, the term “substituted”, whetherpreceded by the term “optionally” or not, means that one or morehydrogens of the designated moiety are replaced with a suitablesubstituent. Unless otherwise indicated, an “optionally substituted”group may have a suitable substituent at each substitutable position ofthe group, and when more than one position in any given structure may besubstituted with more than one substituent selected from a specifiedgroup, the substituent may be either the same or different at everyposition. Combinations of substituents envisioned herein are preferablythose that result in the formation of stable or chemically feasiblecompounds. The term “stable”, as used herein, refers to compounds thatare not substantially altered when subjected to conditions to allow fortheir production, detection, and, in certain embodiments, theirrecovery, purification, and use for one or more of the purposesdisclosed herein.

In some chemical structures herein, substituents are shown attached to abond which crosses a bond in a ring of the depicted molecule. This meansthat one or more of the substituents may be attached to the ring at anyavailable position (usually in place of a hydrogen atom of the parentstructure). In cases where an atom of a ring so substituted has twosubstitutable positions, two groups may be present on the same ringatom. When more than one substituent is present, each is definedindependently of the others, and each may have a different structure. Incases where the substituent shown crossing a bond of the ring is —R,this has the same meaning as if the ring were said to be “optionallysubstituted” as described in the preceding paragraph.

Suitable monovalent substituents on a substitutable carbon atom of an“optionally substituted” group are independently halogen;—(CH₂)₀₋₄R^(∘); —(CH₂)₀₋₄OR^(∘); —O—(CH₂)₀₋₄C(O)OR^(∘);—(CH₂)₀₋₄CH(OR^(∘))₂; —(CH₂)₀₋₄SR^(∘); —(CH₂)₀₋₄Ph, which may besubstituted with R^(∘); —(CH₂)₀₋₄O(CH₂)₀₋₁Ph which may be substitutedwith R^(∘); —CH═CHPh, which may be substituted with R^(∘); —NO₂; —CN;—N₃; —(CH₂)₀₋₄N(R^(∘))₂; —(CH₂)₀₋₄N(R^(∘))C(O)R^(∘); —N(R^(∘))C(S)R^(∘);—(CH₂)₀₋₄N(R^(∘))C(O)NR^(∘) ₂; —N(R^(∘))C(S)NR^(∘) ₂;—(CH₂)₀₋₄N(R^(∘))C(O)OR^(∘); —N(R^(∘))N(R^(∘))C(O)R^(∘);—N(R^(∘))N(R^(∘))C(O)NR^(∘) ₂; —N(R^(∘))N(R^(∘))C(O)OR^(∘);—(CH₂)₀₋₄C(O)R^(∘); —C(S)R^(∘); —(CH₂)₀₋₄C(O)OR^(∘);—(CH₂)₀₋₄C(O)N(R^(∘))₂; —(CH₂)₀₋₄C(O)SR^(∘); —(CH₂)₀₋₄C(O)OSiR₃;—(CH₂)₀₋₄OC(O)R^(∘); —OC(O)(CH₂)₀₋₄SR^(∘); —SC(S)SR^(∘);—(CH₂)₀₋₄SC(O)R^(∘); —(CH₂)₀₋₄C(O)NR^(∘) ₂; —C(S)NR^(∘) ₂; —C(S)SR^(∘);—SC(S)SR^(∘); —(CH₂)₀₋₄OC(O)NR^(∘) ₂; —C(O)N(OR^(∘))R^(∘);—C(O)C(O)R^(∘); —C(O)CH₂C(O)R^(∘); —C(NOR^(∘))R^(∘); —(CH₂)₀₋₄SSR^(∘);—(CH₂)₀₋₄S(O)₂R^(∘); —(CH₂)₀₋₄S(O)₂OR^(∘); —(CH₂)₀₋₄OS(O)₂R^(∘);—S(O)₂NR^(∘) ₂; —(CH₂)₀₋₄S(O)R^(∘); —N(R^(∘))S(O)₂NR^(∘) ₂;—N(R^(∘))S(O)₂R^(∘); —N(OR^(∘))R^(∘); —C(NH)NR^(∘) ₂; —P(O)₂R^(∘);—P(O)R^(∘) ₂; —OP(O)R^(∘) ₂; —OP(O)(OR^(∘))₂; SiR₃; —(C₁₋₄ straight orbranched alkylene)O—N(R^(∘))₂; or —(C₁₋₄ straight or branchedalkylene)C(O)O—N(R^(∘))₂, wherein each R^(∘) may be substituted asdefined below and is independently hydrogen, C₁₋₈ aliphatic, —CH₂Ph,—O(CH₂)₀₋₁Ph, or a 5-6-membered saturated, partially unsaturated, oraryl ring having 0-4 heteroatoms independently selected from nitrogen,oxygen, and sulfur, or, notwithstanding the definition above, twoindependent occurrences of R^(∘), taken together with their interveningatom(s), form a 3-12-membered saturated, partially unsaturated, or arylmono- or polycyclic ring having 0-4 heteroatoms independently selectedfrom nitrogen, oxygen, and sulfur, which may be substituted as definedbelow.

Suitable monovalent substituents on R^(∘) (or the ring formed by takingtwo independent occurrences of R^(∘) together with their interveningatoms), are independently halogen, —(CH₂)₀₋₂R^(●), -(haloR^(●)),—(CH₂)₀₋₂OH, —(CH₂)₀₋₂OR^(●), —(CH₂)₀₋₂CH(OR^(●))₂; —O(haloR^(●)), —CN,—N₃, —(CH₂)₀₋₂C(O)R^(●), —(CH₂)₀₋₂C(O)OH, —(CH₂)₀₋₂C(O)OR^(●),—(CH₂)₀₋₄C(O)N(R^(∘))₂; —(CH₂)₀₋₂SR^(●), —(CH₂)₀₋₂SH, —(CH₂)₀₋₂NH₂,—(CH₂)₀₋₂NHR^(●), —(CH₂)₀₋₂NR^(●) ₂, —NO₂, —SiR^(●) ₃, —OSiR^(●) ₃,—C(O)SR^(●), —(C₁₋₄ straight or branched alkylene)C(O)OR^(●), or—SSR^(●) wherein each R^(●) is unsubstituted or where preceded by “halo”is substituted only with one or more halogens, and is independentlyselected from C₁₋₄ aliphatic, —CH₂Ph, —O(CH₂)₀₋₁Ph, or a 5-6-memberedsaturated, partially unsaturated, or aryl ring having 0-4 heteroatomsindependently selected from nitrogen, oxygen, and sulfur. Suitabledivalent substituents on a saturated carbon atom of R^(∘) include ═O and═S.

Suitable divalent substituents on a saturated carbon atom of an“optionally substituted” group include the following: ═O, ═S, ═NNR*₂,═NNHC(O)R*, ═NNHC(O)OR*, ═NNHS(O)₂R*, ═NR*, ═NOR*, —O(C(R*₂))₂₋₃O—, or—S(C(R*₂))₂₋₃S—, wherein each independent occurrence of R* is selectedfrom hydrogen, C₁₋₆ aliphatic which may be substituted as defined below,or an unsubstituted 5-6-membered saturated, partially unsaturated, oraryl ring having 0-4 heteroatoms independently selected from nitrogen,oxygen, and sulfur. Suitable divalent substituents that are bound tovicinal substitutable carbons of an “optionally substituted” groupinclude: —O(CR*₂)₂₋₃O—, wherein each independent occurrence of R* isselected from hydrogen, C₁₋₆ aliphatic which may be substituted asdefined below, or an unsubstituted 5-6-membered saturated, partiallyunsaturated, or aryl ring having 0-4 heteroatoms independently selectedfrom nitrogen, oxygen, and sulfur.

Suitable substituents on the aliphatic group of R* include halogen,—R^(●), -(haloR^(●)), —OH, —OR^(●), —O(haloR^(●)), —CN, —C(O)OH,—C(O)OR^(●), —NH₂, —NHR^(●), —NR^(●) ₂, or —NO₂, wherein each R^(●) isunsubstituted or where preceded by “halo” is substituted only with oneor more halogens, and is independently C₁₋₄ aliphatic, —CH₂Ph,—O(CH₂)₀₋₁Ph, or a 5-6-membered saturated, partially unsaturated, oraryl ring having 0-4 heteroatoms independently selected from nitrogen,oxygen, and sulfur.

Suitable substituents on a substitutable nitrogen of an “optionallysubstituted” group include —R^(†), —NR^(†) ₂, —C(O)R^(†), —C(O)OR^(†),—C(O)C(O)R^(†), —C(O)CH₂C(O)R^(†), —S(O)₂R^(†), —S(O)₂NR^(†) ₂,—C(S)NR^(†) ₂, —C(NH)NR^(†) ₂, or —N(R^(†))S(O)₂R^(†); wherein eachR^(†) is independently hydrogen, C₁₋₆ aliphatic which may be substitutedas defined below, unsubstituted —OPh, or an unsubstituted 5-6-memberedsaturated, partially unsaturated, or aryl ring having 0-4 heteroatomsindependently selected from nitrogen, oxygen, and sulfur, or,notwithstanding the definition above, two independent occurrences ofR^(†), taken together with their intervening atom(s) form anunsubstituted 3-12-membered saturated, partially unsaturated, or arylmono- or bicyclic ring having 0-4 heteroatoms independently selectedfrom nitrogen, oxygen, and sulfur.

Suitable substituents on the aliphatic group of R^(†) are independentlyhalogen, —R^(●), -(haloR^(●)), —OH, —OR^(●), —O(haloR^(●)), —CN,—C(O)OH, —C(O)OR^(●), —NH₂, —NHR^(●), —NR^(●) ₂, or —NO₂, wherein eachR^(●) is unsubstituted or where preceded by “halo” is substituted onlywith one or more halogens, and is independently C₁₋₄ aliphatic, —CH₂Ph,—O(CH₂)₀₋₁Ph, or a 5-6-membered saturated, partially unsaturated, oraryl ring having 0-4 heteroatoms independently selected from nitrogen,oxygen, and sulfur.

As used herein, the term “reaction zone” refers to a reactor or portionthereof where a particular reaction occurs. A given reaction may occurin multiple reaction zones, and different reaction zones may compriseseparate reactors or portions of the same reactor. A “reactor” typicallycomprises one or more vessels with one or more connections to otherreactors or system components.

As used herein, the terms “reaction stream” and “inlet stream” refer toa solid, liquid or gas medium comprising a reactant that enters areaction zone. As used herein, the terms “product stream” and “outletstream” refer to a solid, liquid or gas medium comprising a product thatexits a reaction zone. Each reaction and product (referring to inlet oroutlet, respectively) stream may be neat with respect to reactant andproduct or they may include co-reactants, co-products, catalysts,solvents, carrier gas and/or impurities.

The term “polymer”, as used herein, refers to a molecule comprisingmultiple repeating units. In some variations, the polymer is a moleculeof high relative molecular mass, the structure of which comprises themultiple repetition of units derived, actually or conceptually, frommolecules of low relative molecular mass. In certain embodiments, apolymer is comprised of only one monomer species (e.g., polyethyleneoxide). In certain embodiments, a polymer may be a copolymer,terpolymer, heteropolymer, block copolymer, or tapered heteropolymer ofone or more epoxides. In one variation, the polymer may be a copolymer,terpolymer, heteropolymer, block copolymer, or tapered heteropolymer oftwo or more monomers.

In some variations, the term “glycidyl”, as used herein, refers to anoxirane substituted with a hydroxyl methyl group or a derivativethereof. In other variations, the term glycidyl as used herein is meantto include moieties having additional substitution on one or more of thecarbon atoms of the oxirane ring or on the methylene group of thehydroxymethyl moiety, examples of such substitution may include, forexample, alkyl groups, halogen atoms, and aryl groups. The termsglycidyl ester, glycidyl acrylate, glydidyl ether etc. denotesubstitution at the oxygen atom of the above-mentioned hydroxymethylgroup, e.g., that oxygen atom is bonded to an acyl group, an acrylategroup, or an alkyl group respectively.

The term “acrylate” or “acrylates” as used herein refer to any acylgroup having a vinyl group adjacent to the acyl carbonyl. The termsencompass mono-, di- and tri-substituted vinyl groups. Acrylates mayinclude, for example, acrylate, methacrylate, ethacrylate, cinnamate(3-phenylacrylate), crotonate, tiglate, and senecioate.

As used herein, the terms “crude acrylic acid” and “glacial acrylicacid” (GAA) describe AA of relatively low and high purity, respectively.Crude AA (also called technical grade AA) has a typical minimum overallpurity level of 94%, by weight, and can be used to make acrylic estersfor paint, adhesive, textile, paper, leather, fiber, and plasticadditive applications. GAA has a typical overall purity level rangingfrom 98% to 99.99% and can be used to make polyacrylic acid (PAA), or asalt thereof, for superabsorbent polymers (SAPs) in disposable diapers,training pants, adult incontinence undergarments and sanitary napkins.PAA, or a salt thereof, is also used in compositions for paper and watertreatment, and in detergent co-builder applications. In some variations,acrylic acid has a purity of at least 98%, at least 98.5%, at least 99%,at least 99.1%, at least 99.2%, at least 99.3%, at least 99.4%, at least99.5%, at least 99.6%, at least 99.7%, at least 99.8%, or at least99.9%; or between 99% and 99.95%, between 99.5% and 99.95%, between99.6% and 99.95%, between 99.7% and 99.95%, or between 99.8% and 99.95%.

Suitable salts of PAA include metal salts, such those of any alkali(e.g., Na⁺, K⁺) cations, alkaline earth cations. In certain embodiments,the PAA salt is the Na⁺ salt, i.e., sodium PAA. In certain embodiments,the salt is the K⁺ salt, i.e., potassium PAA.

Impurities in GAA are reduced to an extent possible to facilitate ahigh-degree of polymerization to PAA, or a salt thereof, and avoidadverse effects from side products in end applications. For example,aldehyde impurities in AA hinder polymerization and may discolor thePAA. Maleic anhydride impurities form undesirable copolymers which maybe detrimental to polymer properties. Carboxylic acids, e.g., saturatedcarboxylic acids that do not participate in the polymerization, canaffect the final odor of PAA, or a salt thereof, or SAP-containingproducts and/or detract from their use. For example, foul odors mayemanate from SAP that contains acetic acid or propionic acid and skinirritation may result from SAP that contains formic acid.

The reduction or removal of impurities from petroleum-based AA iscostly, whether to produce petroleum-based crude AA or petroleum-basedglacial AA. Costly multistage distillations and/or extraction and/orcrystallizations steps are generally employed (e.g., as described inU.S. Pat. Nos. 5,705,688 and 6,541,665). Notable impurities frompetroleum-based AA that are reduced and/or eliminated from the disclosedcompositions include, for example, aldehyde impurities and products orbyproducts of propylene oxidation.

As used herein, the term “product or byproduct of propylene oxidation”or “compound that derives from the oxidation of propylene” are usedinterchangeably to refer to products and byproducts of propyleneoxidation including, for example, C₁ compounds such as formaldehyde, andformic acid; C₂ compounds such as acetaldehyde, acetic acid; C₃compounds such as propylene, allyl alcohol, acrolein (i.e., propenal),propanol, isopropyl alcohol, acetone, propionic acid; C₄ compounds suchas maleic anhydride; and C₅ compounds such as furfural, etc.

As used herein, the term “aldehyde impurity” includes any of thealdehydes in the preceding paragraph.

As used herein, the term “substantially free” means, in some variations,less than 5 wt %, 1 wt %, 0.1 wt %, 0.01 wt %, or a range including anytwo of these values, or less than 10,000 ppm, 1,000 ppm, 500 ppm, 100ppm, 50 ppm, 10 ppm, or a range including any two of these values. Inone variation, a composition that is substantially free of Compound Ahas less than 5%, less than 4%, less than 3%, less than 2%, less than1%, less than 0.9%, less than 0.8%, less than 0.7%, less than 0.6%, lessthan 0.5%, less than 0.4%, less than 0.3%, less than 0.2%, less than0.1%, less than 0.05%, less than 0.01%, or less than 0.001%, by weight,or a range including any two of the aforementioned values, of CompoundA.

Stabilizers are commonly used to preserve AA. As used herein, the term“stabilizer” includes any radical polymerization inhibitor or ananti-foaming agent. AA is susceptible to unwanted Michael addition toitself and to unwanted free-radical polymerization with itself, whichmay be counteracted by addition of polymerization inhibitors to the AA.Suitable polymerization inhibitors include, for example, hydroquinonemonomethyl ether, MEHQ, alkylphenols, such as o-, m- or p-cresol(methylphenol), 2-tert-butyl-4-methylphenol,6-tert-butyl-2,4-dimethylphenol, 2,6-di-tert-butyl-4-methylphenol,2-tert-butylphenol, 4-tert-butylphenol, 2,4-di-tert-butylphenol and2-methyl-4-tert-butylphenol and hydroxyphenols such as hydroquinone,catechol, resorcinol, 2-methylhydroquinone and2,5-di-tert-butylhydroquinone. Examples of anti-foaming agents includesilicones (e.g., polydimethylsiloxanes), alcohols, stearates, andglycols.

As used herein, the term “about” preceding one or more numerical valuesmeans the numerical value ±5%. It should be understood that reference to“about” a value or parameter herein includes (and describes) embodimentsthat are directed to that value or parameter per se. For example,description referring to “about x” includes description of “x” per se.

DETAILED DESCRIPTION

Described herein are systems and methods for producing polyacrylic acid(PAA) from ethylene, rather than propylene, that eliminate products andbyproducts of propylene oxidation. Also, because the disclosed systemsand methods are conducted with a single integrated system, highlyreactive intermediates, including ethylene oxide (EO), betapropiolactone (BPL), and acrylic acid are swiftly carried through to therelatively stable polyacrylic acid (PAA). The disclosed systems andmethods can be used to prepare PAA and SAPs of excellent (e.g., high)purity.

Systems

Provided herein are systems for producing PAA and/or SAP from ethylenewithin an integrated system. In one aspect, a system is provided for theproduction of polyacrylic acid (PAA) from ethylene, within an integratedsystem, comprising:

-   -   an oxidative reactor, comprising an inlet fed by ethylene, an        oxidative reaction zone that converts at least some of the        ethylene to ethylene oxide (EO), and an outlet which provides an        outlet stream comprising the EO,    -   a central reactor, comprising an inlet fed by an EO source, and        a carbon monoxide (CO) source, a central reaction zone that        converts at least some of the EO to beta propiolactone (BPL) or        polypropiolactone (PPL), and an outlet which provides an outlet        stream comprising the BPL or PPL,    -   one or more of (i), (ii) and (iii):        -   (i) a first reactor, comprising an inlet fed by the outlet            stream comprising BPL of the central reactor, a first            reaction zone that converts at least some of the BPL to AA,            and an outlet which provides an outlet stream comprising the            AA,        -   (ii) a second (a) reactor, comprising an inlet fed by the            outlet stream comprising BPL of the central reactor, a            second (a) reaction zone that converts at least some of the            BPL to PPL, and an outlet which provides an outlet stream            comprising the PPL, and a second (b) reactor, comprising an            inlet fed by the outlet stream comprising PPL of the            second (a) reactor, a second (b) reaction zone that converts            at least some of the PPL to AA, and an outlet which provides            an outlet stream comprising the AA, and        -   (iii) a third reactor, comprising an inlet fed by the outlet            stream comprising PPL of the central reactor, a third            reaction zone that converts at least some of the PPL to a            third product, and an outlet which provides an outlet stream            comprising the AA, and        -   (iv) a fourth reactor, comprising an inlet fed by the outlet            stream comprising AA of one or more of the first, second (b)            and third reactor, a fourth reaction zone that converts at            least some of the AA to polyacrylic acid (PAA), or a salt            thereof, and an outlet which provides an outlet stream            comprising the PAA, or a salt thereof, and    -   a controller for independently modulating production of the EO,        BPL, PPL, AA and PAA.

In some variations, provided is a system for producing polyacrylic acid(PAA) from ethylene, comprising:

-   -   an oxidative reactor, comprising:        -   an inlet configured to receive ethylene,        -   an oxidative reaction zone configured to convert at least            some of the ethylene to ethylene oxide (EO), and        -   an outlet configured to provide an EO stream comprising the            EO;    -   a central reactor, comprising:        -   an inlet configured to receive EO from the EO stream of the            oxidative reactor, and carbon monoxide (CO) from a CO            source,        -   a central reaction zone configured to convert at least some            of the EO to beta propiolactone (BPL) or polypropiolactone            (PPL), or a combination thereof, and        -   an outlet configured to provide a carbonylation stream            comprising the BPL, or a carbonylation stream comprising the            PPL, or a combination thereof;    -   one or more of (i), (ii) and (iii):        -   (i) a first reactor, comprising:            -   an inlet configured to receive BPL from the                carbonylation stream of the central reactor,            -   a first reaction zone configured to convert at least                some of the BPL to AA, and            -   an outlet configured to provide an AA stream comprising                the AA,        -   (ii) a second (a) reactor, comprising:            -   an inlet configured to receive BPL from the                carbonylation stream of the central reactor,            -   a second (a) reaction zone configured to convert at                least some of the BPL to PPL, and            -   an outlet configured to provide a PPL stream comprising                the PPL, and        -   a second (b) reactor, comprising:            -   an inlet configured to receive the PPL stream of the                second (a) reactor,            -   a second (b) reaction zone configured to convert at                least some of the PPL to AA, and            -   an outlet configured to provide an AA stream comprising                the AA, and        -   (iii) a third reactor, comprising:            -   an inlet configured to receive PPL from carbonylation                stream of the central reactor,            -   a third reaction zone configured to convert at least                some of the PPL to AA, and            -   an outlet configured to provide an AA stream comprising                the AA;    -   a fourth reactor, comprising:        -   an inlet configured to receive the AA stream of one or more            of the first, second (b) and third reactor,        -   a fourth reaction zone configured to convert at least some            of the AA to polyacrylic acid (PAA), or a salt thereof, and        -   an outlet configured to provide a PAA stream comprising the            PAA, or a salt thereof; and    -   a controller to independently modulate production of the EO,        BPL, PPL, AA and PAA.

In one embodiment, the system comprises (i). Thus, in one variation,provided is a system for producing polyacrylic acid (PAA) from ethylene,within an integrated system, comprising:

an oxidative reactor, comprising:

-   -   an inlet configured to receive ethylene,        -   an oxidative reaction zone configured to convert at least            some of the ethylene to ethylene oxide (EO), and        -   an outlet configured to provide an EO stream comprising the            EO;    -   a central reactor, comprising:        -   an inlet configured to receive EO from the EO stream of the            oxidative reactor, and carbon monoxide (CO) from a CO            source,        -   a central reaction zone configured to convert at least some            of the EO to beta propiolactone (BPL) or polypropiolactone            (PPL), or a combination thereof, and        -   an outlet configured to provide a carbonylation stream            comprising the BPL;    -   an acrylic acid (AA) reactor (also referred to in FIG. 1 as        first reactor), comprising:        -   an inlet configured to receive BPL from the carbonylation            stream of the central reactor,        -   a reaction zone configured to convert at least some of the            BPL to AA, and        -   an outlet configured to provide an AA stream comprising the            AA,    -   a PAA reactor, comprising:        -   an inlet configured to receive AA from the AA stream of the            AA reactor,        -   a reaction zone configured to convert at least some of the            AA to polyacrylic acid (PAA), or a salt thereof, and        -   an outlet configured to provide a PAA stream comprising the            PAA, or a salt thereof; and    -   a controller to independently modulate production of the EO,        BPL, AA and PAA.

In another embodiment, the system comprises (ii). Thus, in onevariation, provided is a system for producing polyacrylic acid (PAA)from ethylene, within an integrated system, comprising:

-   -   an oxidative reactor, comprising:        -   an inlet configured to receive ethylene,        -   an oxidative reaction zone configured to convert at least            some of the ethylene to ethylene oxide (EO), and        -   an outlet configured to provide an EO stream comprising the            EO;    -   a central reactor, comprising:        -   an inlet configured to receive EO from the EO stream of the            oxidative reactor, and carbon monoxide (CO) from a CO            source,        -   a central reaction zone configured to convert at least some            of the EO to beta propiolactone (BPL) or polypropiolactone            (PPL), or a combination thereof, and        -   an outlet configured to provide a carbonylation stream            comprising the BPL;    -   a PPL reactor (also referred to in FIG. 1 as second (a)        reactor), comprising:        -   an inlet configured to receive BPL from the carbonylation            stream of the central reactor,        -   a reaction zone configured to convert at least some of the            BPL to PPL, and        -   an outlet configured to provide a PPL stream comprising the            PPL;    -   an AA reactor (also referred to in FIG. 1 as second (b)        reactor), comprising:        -   an inlet configured to receive the PPL stream,        -   a reaction zone configured to convert at least some of the            PPL to AA, and        -   an outlet configured to provide an AA stream comprising the            AA;    -   a PAA reactor, comprising:        -   an inlet configured to receive AA from the AA stream of the            AA reactor,        -   a reaction zone configured to convert at least some of the            AA to polyacrylic acid (PAA), or a salt thereof, and        -   an outlet configured to provide a PAA stream comprising the            PAA, or a salt thereof; and    -   a controller to independently modulate production of the EO,        BPL, AA and PAA.

In another embodiment, the system comprises (iii). Thus, in anothervariation, provided is a system for producing polyacrylic acid (PAA)from ethylene, within an integrated system, comprising:

-   -   an oxidative reactor, comprising:        -   an inlet configured to receive ethylene,        -   an oxidative reaction zone configured to convert at least            some of the ethylene to ethylene oxide (EO), and        -   an outlet configured to provide an EO stream comprising the            EO;    -   a central reactor, comprising:        -   an inlet configured to receive EO from the EO stream of the            oxidative reactor, and carbon monoxide (CO) from a CO            source,        -   a central reaction zone configured to convert at least some            of the EO to beta propiolactone (BPL) or polypropiolactone            (PPL), or a combination thereof, and        -   an outlet configured to provide a carbonylation stream            comprising the PPL;    -   an AA reactor (also referred to in FIG. 1 as third reactor),        comprising:        -   an inlet configured to receive PPL from the carbonylation            stream of the central reactor,        -   a reaction zone configured to convert at least some of the            PPL to AA, and an outlet configured to provide an AA stream            comprising the AA;    -   a PAA reactor, comprising:        -   an inlet configured to receive AA from the AA stream of the            AA reactor,        -   a reaction zone configured to convert at least some of the            AA to polyacrylic acid (PAA), or a salt thereof, and        -   an outlet configured to provide a PAA stream comprising the            PAA, or a salt thereof; and    -   a controller to independently modulate production of the EO,        PPL, AA and PAA.

In certain embodiments, the system comprises two of (i), (ii) and (iii).For example, in one embodiment, the system comprises (i) and (iii).Thus, in one variation, provided is a system for producing polyacrylicacid (PAA) from ethylene, within an integrated system, comprising:

-   -   an oxidative reactor, comprising:        -   an inlet configured to receive ethylene,        -   an oxidative reaction zone configured to convert at least            some of the ethylene to ethylene oxide (EO), and        -   an outlet configured to provide an EO stream comprising the            EO;    -   a central reactor, comprising:        -   an inlet configured to receive EO from the EO stream of the            oxidative reactor, and carbon monoxide (CO) from a CO            source,        -   a central reaction zone configured to convert at least some            of the EO to beta propiolactone (BPL) and polypropiolactone            (PPL), and        -   an outlet configured to provide a first carbonylation stream            comprising the BPL, and a second carbonylation stream            comprising the PPL;    -   a first AA reactor (also referred to in FIG. 1 as first        reactor), comprising:        -   an inlet configured to receive BPL from the first            carbonylation stream of the central reactor,        -   a reaction zone configured to convert at least some of the            BPL to AA, and        -   an outlet configured to provide a first AA stream comprising            the AA;    -   a second AA reactor (also referred to in FIG. 1 as third        reactor), comprising:        -   an inlet configured to receive PPL from the second            carbonylation stream of the central reactor,        -   a reaction zone configured to convert at least some of the            PPL to AA, and        -   an outlet configured to provide a second AA stream            comprising the AA;    -   a PAA reactor, comprising:        -   at least one inlet configured to receive AA from one or both            of the first AA stream and the second AA stream,        -   a reaction zone configured to convert at least some of the            AA to polyacrylic acid (PAA), or a salt thereof, and        -   an outlet configured to provide a PAA stream comprising the            PAA, or a salt thereof; and    -   a controller to independently modulate production of the EO,        BPL, PPL, AA and PAA.

In another embodiment, the system comprises (ii) and (iii). Thus, inanother variation, provided is a system for producing polyacrylic acid(PAA) from ethylene, within an integrated system, comprising:

-   -   an oxidative reactor, comprising:        -   an inlet configured to receive ethylene,        -   an oxidative reaction zone configured to convert at least            some of the ethylene to ethylene oxide (EO), and        -   an outlet configured to provide an EO stream comprising the            EO;    -   a central reactor, comprising:        -   an inlet configured to receive EO from the EO stream of the            oxidative reactor, and carbon monoxide (CO) from a CO            source,        -   a central reaction zone configured to convert at least some            of the EO to beta propiolactone (BPL) and polypropiolactone            (PPL), and        -   an outlet configured to provide a first carbonylation stream            comprising the BPL, and a second carbonylation stream            comprising the PPL;    -   a PPL reactor (also referred to in FIG. 1 as second (a)        reactor), comprising:        -   an inlet configured to receive BPL from the first            carbonylation stream of the central reactor,        -   a reaction zone configured to convert at least some of the            BPL to PPL, and        -   an outlet configured to provide a PPL stream comprising the            PPL;    -   a first AA reactor (also referred to in FIG. 1 as second (b)        reactor), comprising:        -   an inlet configured to receive PPL from the PPL stream of            the PPL reactor,        -   a reaction zone configured to convert at least some of the            PPL to AA, and        -   an outlet configured to provide a first AA stream comprising            the AA;    -   a second AA reactor (also referred to in FIG. 1 as third        reactor), comprising:        -   an inlet configured to receive PPL from the second            carbonylation stream of the central reactor,        -   a reaction zone configured to convert at least some of the            PPL to AA, and        -   an outlet configured to provide a second AA stream            comprising the AA;    -   a PAA reactor, comprising:        -   at least one inlet configured to receive AA from one or both            of the first AA stream and the second AA stream,        -   a reaction zone configured to convert at least some of the            AA to polyacrylic acid (PAA), or a salt thereof, and        -   an outlet configured to provide a PAA stream comprising the            PAA, or a salt thereof; and    -   a controller to independently modulate production of the EO,        BPL, PPL, AA and PAA.

In some variations of the foregoing system, the first and second AAreactors may be the same reactor. In other variations, the first andsecond reactors are separate reactors.

In another embodiment, the system comprises (i) and (ii). Thus, in yetanother variation, provided is a system for producing polyacrylic acid(PAA) from ethylene, within an integrated system, comprising:

-   -   an oxidative reactor, comprising:        -   an inlet configured to receive ethylene,        -   an oxidative reaction zone configured to convert at least            some of the ethylene to ethylene oxide (EO), and        -   an outlet configured to provide an EO stream comprising the            EO;    -   a central reactor, comprising:        -   an inlet configured to receive EO from the EO stream of the            oxidative reactor, and carbon monoxide (CO) from a CO            source,        -   a central reaction zone configured to convert at least some            of the EO to beta propiolactone (BPL), and        -   an outlet configured to provide a BPL stream comprising the            BPL;    -   a first AA reactor (also referred to in FIG. 1 as first        reactor), comprising:        -   an inlet configured to receive at least a portion of the BPL            stream,        -   a reaction zone configured to convert at least some of the            BPL to AA, and        -   an outlet configured to provide a first AA stream comprising            the AA;    -   a PPL reactor (also referred to in FIG. 1 as second (a)        reactor), comprising:        -   an inlet configured to receive at least a portion of the BPL            stream,        -   a reaction zone configured to convert at least some of the            BPL to PPL, and        -   an outlet configured to provide a PPL stream comprising the            PPL;    -   a second AA reactor (also referred to in FIG. 1 as second (b)        reactor), comprising:        -   an inlet configured to receive PPL from the PPL stream,        -   a reaction zone configured to convert at least some of the            PPL to AA, and        -   an outlet configured to provide a second AA stream            comprising the AA;    -   a PAA reactor, comprising:        -   at least one inlet configured to receive AA from one or both            of the first AA stream and the second AA stream,        -   a reaction zone configured to convert at least some of the            AA to polyacrylic acid (PAA), or a salt thereof, and        -   an outlet configured to provide a PAA stream comprising the            PAA, or a salt thereof; and    -   a controller to independently modulate production of the EO,        BPL, PPL, AA and PAA.

In some variations of the foregoing system, the first and second AAreactors may be the same reactor. In other variations, the first andsecond AA reactors are separate reactors.

In some variations of the foregoing system where the first and second AAreactors are separate, the PAA reactor is configured to receive AA fromboth of the AA streams. For example, AA from the first AA stream and AAfrom the second AA stream may be combined, and in some variations, thiscombination may occur either at the inlet of the PAA reactor or at apoint prior to the PAA reactor inlet. In other variations, the PAAreactor is configured to receive AA exclusively from the first AA streamor exclusively from the second AA stream. In some variations the systemincludes provision to allow an operator to control the ratio of the AAprovided from the first AA stream and AA provided from the second AAstream and to change the ratio over time.

In certain embodiments, the system comprises all of (i), (ii) and (iii).Thus, in one variation, provided is a system for producing polyacrylicacid (PAA) from ethylene, within an integrated system, comprising:

-   -   an oxidative reactor, comprising:        -   an inlet configured to receive ethylene,        -   an oxidative reaction zone configured to convert at least            some of the ethylene to ethylene oxide (EO), and        -   an outlet configured to provide an EO stream comprising the            EO;    -   a central reactor, comprising:        -   an inlet configured to receive EO from the EO stream of the            oxidative reactor, and carbon monoxide (CO) from a CO            source,        -   a central reaction zone configured to convert at least some            of the EO to beta propiolactone (BPL) and polypropiolactone            (PPL), and        -   an outlet configured to provide a first carbonylation stream            comprising the BPL, and a second carbonylation stream            comprising the PPL;    -   a first AA reactor (also referred to in FIG. 1 as the first        reactor), comprising:        -   an inlet configured to receive at least a portion of the            first carbonylation stream of the central reactor,        -   a reaction zone configured to convert at least some of the            BPL to AA, and        -   an outlet configured to provide a first AA stream comprising            the AA;    -   a PPL reactor (also referred to in FIG. 1 as second (a)        reactor), comprising:        -   an inlet configured to receive at least a portion of the            first carbonylation stream,        -   a reaction zone configured to convert at least some of the            BPL to PPL, and        -   an outlet configured to provide a PPL stream comprising the            PPL;    -   a second AA reactor (also referred to in FIG. 1 as second (b)        reactor), comprising:        -   an inlet configured to receive PPL from the PPL stream of            the PPL reactor,        -   a reaction zone configured to convert at least some of the            PPL to AA, and        -   an outlet configured to provide a second AA stream            comprising the AA;    -   a third AA reactor (also referred to in FIG. 1 as third        reactor), comprising:        -   an inlet configured to receive PPL from the second            carbonylation stream of the central reactor,        -   a reaction zone configured to convert at least some of the            PPL to AA, and        -   an outlet configured to provide a third AA stream comprising            the AA;    -   a PAA reactor, comprising:        -   an inlet configured to receive AA from one or more of the            first AA stream, the second AA stream, and the third AA            stream,        -   a reaction zone configured to convert at least some of the            AA to polyacrylic acid (PAA), or a salt thereof, and        -   an outlet configured to provide a PAA stream comprising the            PAA, or a salt thereof; and    -   a controller to independently modulate production of the EO,        BPL, PPL, AA and PAA.

In some variations of the foregoing system, the first, second and thirdAA reactors may be the same reactor. In other variations, the first andsecond AA reactors may be the same, and the third AA reactor is aseparate reactor. In yet other variations, the first, second and thirdreactors are all separate reactors.

In some variations of the foregoing system, the PAA reactor isconfigured to receive AA from all of the AA streams. For example, AAfrom the first AA stream AA from the second AA stream, and AA from thethird AA stream may be combined, and in some variations, thiscombination may occur either at the inlet of the PAA reactor or at apoint prior to the PAA reactor inlet. In other variations, the PAAreactor is configured to receive AA exclusively from the first AAstream, exclusively from the second AA stream, or exclusively from thethird AA stream. In some variations the system includes provision toallow an operator to control the source of the AA provided to the PAAreactor and/or to control the ratio of AA supplied from the first AAstream, the second AA stream, and the third AA stream and to changesource or the ratio of sources over time.

In some variations of the foregoing systems, the EO stream received bythe central reactor may be the entire or partial EO stream from theoxidative reactor, and/or may be used directly from the oxidativereactor or be further treated prior to use in the oxidative reactor. Forexample, in one variation, the EO stream of the oxidative reactor may befurther processed before it is fed into the central reactor. Forexample, in one variation, the EO stream of the oxidative reactor may befurther dried and/or purified, prior to feeding into the centralreactor. In other variations of the foregoing, the central reactor mayreceive a fraction of the EO stream provided by the oxidative reactor.

In certain embodiments, the systems described herein produce AA at about200 to about 800 kilotons per annum (kta). In certain embodiments, thesystems described herein can produce AA at about 200, 250, 300, 350,400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1,000kilotons per annum (kta), or within a range including any two of thesevalues.

In certain embodiments, the AA produced by the systems is substantiallyfree of an aldehyde impurity or a compound that derives from theoxidation of propylene. In some embodiments, the AA is substantiallyfree of an aldehyde impurity. In some embodiments, the AA issubstantially free of furfural. In some embodiments, the AA issubstantially free of stabilizers. In some embodiments, the AA issubstantially free of radical polymerization inhibitors. In someembodiments, the AA is substantially free of anti-foam agents.

In certain embodiments, the AA is glacial acrylic acid (GAA). In somevariations, AA has a purity of at least 98%, at least 98.5%, at least99%, at least 99.1%, at least 99.2%, at least 99.3%, at least 99.4%, atleast 99.5%, at least 99.6%, at least 99.7%, at least 99.8%, or at least99.9%; or between 99% and 99.95%, between 99.5% and 99.95%, between99.6% and 99.95%, between 99.7% and 99.95%, or between 99.8% and 99.95%.

In certain embodiments, the GAA is substantially free of an aldehydeimpurity or a compound that derives from the oxidation of propylene. Insome embodiments, the GAA is substantially free of an aldehyde impurity.In some variations, the AA stream has less than 5%, less than 4%, lessthan 3%, less than 2%, less than 1%, less than 0.9%, less than 0.8%,less than 0.7%, less than 0.6%, less than 0.5%, less than 0.4%, lessthan 0.3%, less than 0.2%, less than 0.1%, less than 0.05%, less than0.01%, or less than 0.001%, by weight, or a range including any two ofthe aforementioned values, of an aldehyde impurity. In other variations,the AA stream has less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50ppm, 10 ppm, or a range including any two of the aforementioned values,of an aldehyde impurity.

In other variations, the AA stream has less than 5%, less than 4%, lessthan 3%, less than 2%, less than 1%, less than 0.9%, less than 0.8%,less than 0.7%, less than 0.6%, less than 0.5%, less than 0.4%, lessthan 0.3%, less than 0.2%, less than 0.1%, less than 0.05%, less than0.01%, or less than 0.001%, by weight, or a range including any two ofthe aforementioned values, of a compound that derives from the oxidationof propylene. In other variations, the AA stream has less than 10,000ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10 ppm, or a range includingany two of the aforementioned values, of a compound that derives fromthe oxidation of propylene.

In some embodiments, the GAA is substantially free of furfural. In somevariations, the AA stream has less than 5%, less than 4%, less than 3%,less than 2%, less than 1%, less than 0.9%, less than 0.8%, less than0.7%, less than 0.6%, less than 0.5%, less than 0.4%, less than 0.3%,less than 0.2%, less than 0.1%, less than 0.05%, less than 0.01%, orless than 0.001%, by weight, or a range including any two of theaforementioned values, of furfural. In other variations, the AA streamhas less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10 ppm,or a range including any two of the aforementioned values, of furfural.

In some embodiments, the GAA is substantially free of acetic acid. Insome variations, the AA stream has less than 5%, less than 4%, less than3%, less than 2%, less than 1%, less than 0.9%, less than 0.8%, lessthan 0.7%, less than 0.6%, less than 0.5%, less than 0.4%, less than0.3%, less than 0.2%, less than 0.1%, less than 0.05%, less than 0.01%,or less than 0.001%, by weight, or a range including any two of theaforementioned values, of acetic acid. In other variations, the AAstream has less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10ppm, or a range including any two of the aforementioned values, ofacetic acid.

In some embodiments, the GAA is substantially free of stabilizers. Insome variations, the AA stream has less than 5%, less than 4%, less than3%, less than 2%, less than 1%, less than 0.9%, less than 0.8%, lessthan 0.7%, less than 0.6%, less than 0.5%, less than 0.4%, less than0.3%, less than 0.2%, less than 0.1%, less than 0.05%, less than 0.01%,or less than 0.001%, by weight, or a range including any two of theaforementioned values, of stabilizers. In other variations, the AAstream has less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10ppm, or a range including any two of the aforementioned values, ofstabilizers.

In some embodiments, the GAA is substantially free of radicalpolymerization inhibitors. In some variations, the AA stream has lessthan 5%, less than 4%, less than 3%, less than 2%, less than 1%, lessthan 0.9%, less than 0.8%, less than 0.7%, less than 0.6%, less than0.5%, less than 0.4%, less than 0.3%, less than 0.2%, less than 0.1%,less than 0.05%, less than 0.01%, or less than 0.001%, by weight, or arange including any two of the aforementioned values, of radicalpolymerization inhibitors. In other variations, the AA stream has lessthan 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10 ppm, or a rangeincluding any two of the aforementioned values, of radicalpolymerization inhibitors.

In some embodiments, the GAA is substantially free of anti-foam agents.In some variations, the AA stream has less than 5%, less than 4%, lessthan 3%, less than 2%, less than 1%, less than 0.9%, less than 0.8%,less than 0.7%, less than 0.6%, less than 0.5%, less than 0.4%, lessthan 0.3%, less than 0.2%, less than 0.1%, less than 0.05%, less than0.01%, or less than 0.001%, by weight, or a range including any two ofthe aforementioned values, of anti-foam agents. In other variations, theAA stream has less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm,10 ppm, or a range including any two of the aforementioned values, ofanti-foam agents.

In certain embodiments, the inlet to the fourth reactor (also referredto as the PAA reactor) is fed by one or more reactant streams comprisingsodium hydroxide in the presence of a radical initiator to form a PAAsodium salt.

In certain embodiments, at least some of the AA is converted to the PAA,or a salt thereof, via gel polymerization, suspension polymerization orsolution polymerization.

In certain embodiments, the PAA, or a salt thereof, is substantiallyfree of an aldehyde impurity or a compound that derives from theoxidation of propylene. In some embodiments, the PAA is substantiallyfree of an aldehyde impurity. In some variations, the PAA stream hasless than 5%, less than 4%, less than 3%, less than 2%, less than 1%,less than 0.9%, less than 0.8%, less than 0.7%, less than 0.6%, lessthan 0.5%, less than 0.4%, less than 0.3%, less than 0.2%, less than0.1%, less than 0.05%, less than 0.01%, or less than 0.001%, by weight,or a range including any two of the aforementioned values, of analdehyde impurity. In other variations, the PAA stream has less than10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10 ppm, or a rangeincluding any two of the aforementioned values, of an aldehyde impurity.

In other variations, the PAA stream has less than 5%, less than 4%, lessthan 3%, less than 2%, less than 1%, less than 0.9%, less than 0.8%,less than 0.7%, less than 0.6%, less than 0.5%, less than 0.4%, lessthan 0.3%, less than 0.2%, less than 0.1%, less than 0.05%, less than0.01%, or less than 0.001%, by weight, or a range including any two ofthe aforementioned values, of a compound that derives from the oxidationof propylene. In other variations, the PAA stream has less than 10,000ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10 ppm, or a range includingany two of the aforementioned values, of a compound that derives fromthe oxidation of propylene.

In some embodiments, the PAA is substantially free of furfural. In somevariations, the PAA stream has less than 5%, less than 4%, less than 3%,less than 2%, less than 1%, less than 0.9%, less than 0.8%, less than0.7%, less than 0.6%, less than 0.5%, less than 0.4%, less than 0.3%,less than 0.2%, less than 0.1%, less than 0.05%, less than 0.01%, orless than 0.001%, by weight, or a range including any two of theaforementioned values, of furfural. In other variations, the PAA streamhas less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10 ppm,or a range including any two of the aforementioned values, of furfural.

In some embodiments, the PAA is substantially free of acetic acid. Insome variations, the PAA stream has less than 5%, less than 4%, lessthan 3%, less than 2%, less than 1%, less than 0.9%, less than 0.8%,less than 0.7%, less than 0.6%, less than 0.5%, less than 0.4%, lessthan 0.3%, less than 0.2%, less than 0.1%, less than 0.05%, less than0.01%, or less than 0.001%, by weight, or a range including any two ofthe aforementioned values, of acetic acid. In other variations, the PAAstream has less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10ppm, or a range including any two of the aforementioned values, ofacetic acid.

In some embodiments, the PAA is substantially free of stabilizers. Insome variations, the PAA stream has less than 5%, less than 4%, lessthan 3%, less than 2%, less than 1%, less than 0.9%, less than 0.8%,less than 0.7%, less than 0.6%, less than 0.5%, less than 0.4%, lessthan 0.3%, less than 0.2%, less than 0.1%, less than 0.05%, less than0.01%, or less than 0.001%, by weight, or a range including any two ofthe aforementioned values, of stabilizers. In other variations, the PAAstream has less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10ppm, or a range including any two of the aforementioned values, ofstabilizers.

In some embodiments, the PAA is substantially free of radicalpolymerization inhibitors. In some variations, the PAA stream has lessthan 5%, less than 4%, less than 3%, less than 2%, less than 1%, lessthan 0.9%, less than 0.8%, less than 0.7%, less than 0.6%, less than0.5%, less than 0.4%, less than 0.3%, less than 0.2%, less than 0.1%,less than 0.05%, less than 0.01%, or less than 0.001%, by weight, or arange including any two of the aforementioned values, of radicalpolymerization inhibitors. In other variations, the PAA stream has lessthan 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10 ppm, or a rangeincluding any two of the aforementioned values, of radicalpolymerization inhibitors.

In some embodiments, the PAA is substantially free of anti-foam agents.In some variations, the PAA stream has less than 5%, less than 4%, lessthan 3%, less than 2%, less than 1%, less than 0.9%, less than 0.8%,less than 0.7%, less than 0.6%, less than 0.5%, less than 0.4%, lessthan 0.3%, less than 0.2%, less than 0.1%, less than 0.05%, less than0.01%, or less than 0.001%, by weight, or a range including any two ofthe aforementioned values, of anti-foam agents. In other variations, thePAA stream has less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50ppm, 10 ppm, or a range including any two of the aforementioned values,of anti-foam agents.

In certain embodiments, the inlet to the fourth reactor (also referredto as the PAA reactor) is further fed by one or more reactant streamseach comprising a monomer to co-polymerize with GAA to form one or moreco-polymers of PAA selected from a polyacrylamide copolymer, ethylenemaleic anhydride copolymer, cross-linked carboxymethylcellulosecopolymer, polyvinyl alcohol copolymer, cross-linked polyethylene oxidecopolymer, and starch grafted polyacrylonitrile copolymer of PAA.

In certain embodiments, the system further comprises:

-   -   (v) a fifth reactor, comprising an inlet fed by the outlet        stream comprising PAA, or a salt thereof, of the fourth reactor,        a fifth reaction zone that converts at least some of the PAA, or        a salt thereof, to superabsorbent polymer (SAP) and an outlet        which provides an outlet stream comprising the SAP.

In one variation, the systems described herein further comprise:

-   a SAP reactor, comprising:    -   an inlet configured to receive PAA from the PAA stream,    -   a reaction zone configured to convert at least some of the PAA,        or a salt thereof, to SAP, and    -   an outlet configured to provide a SAP stream comprising the SAP.

In certain embodiments, the inlet to the fifth reactor (also referred toas the SAP reactor) is further fed by one or more reactant streams eachcomprising a cross-linking agent may be sprayed on the PAA, or a saltthereof.

It should generally be understood that reference to “a first reactionzone” and “a second reaction zone”, etc., or “a first reactor” and “asecond reactor”, etc., or “a first stream” and “a second stream”, etc.,does not necessarily imply an order of the reaction zones, reactors orstreams. In some variations, the use of such references denotes thenumber of reaction zones, reactors or streams present. In othervariations, an order may be implied by the context in which the reactionzones, reactors or streams are configured or used.

In certain embodiments, the SAP comprises less than about 1000 parts permillion residual monoethylenically unsaturated monomer. In certainembodiments, the SAP is substantially free of an aldehyde impurity or acompound that derives from the oxidation of propylene.

In some embodiments, the SAP is substantially free of an aldehydeimpurity. In some variations, the SAP stream has less than 5%, less than4%, less than 3%, less than 2%, less than 1%, less than 0.9%, less than0.8%, less than 0.7%, less than 0.6%, less than 0.5%, less than 0.4%,less than 0.3%, less than 0.2%, less than 0.1%, less than 0.05%, lessthan 0.01%, or less than 0.001%, by weight, or a range including any twoof the aforementioned values, of an aldehyde impurity. In othervariations, the SAP stream has less than 10,000 ppm, 1,000 ppm, 500 ppm,100 ppm, 50 ppm, 10 ppm, or a range including any two of theaforementioned values, of an aldehyde impurity.

In other variations, the SAP stream has less than 5%, less than 4%, lessthan 3%, less than 2%, less than 1%, less than 0.9%, less than 0.8%,less than 0.7%, less than 0.6%, less than 0.5%, less than 0.4%, lessthan 0.3%, less than 0.2%, less than 0.1%, less than 0.05%, less than0.01%, or less than 0.001%, by weight, or a range including any two ofthe aforementioned values, of a compound that derives from the oxidationof propylene. In other variations, the SAP stream has less than 10,000ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10 ppm, or a range includingany two of the aforementioned values, of a compound that derives fromthe oxidation of propylene.

In some embodiments, the SAP is substantially free of furfural. In somevariations, the SAP stream has less than 5%, less than 4%, less than 3%,less than 2%, less than 1%, less than 0.9%, less than 0.8%, less than0.7%, less than 0.6%, less than 0.5%, less than 0.4%, less than 0.3%,less than 0.2%, less than 0.1%, less than 0.05%, less than 0.01%, orless than 0.001%, by weight, or a range including any two of theaforementioned values, of furfural. In other variations, the SAP streamhas less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10 ppm,or a range including any two of the aforementioned values, of furfural.

In some embodiments, the SAP is substantially free of acetic acid. Insome variations, the SAP stream has less than 5%, less than 4%, lessthan 3%, less than 2%, less than 1%, less than 0.9%, less than 0.8%,less than 0.7%, less than 0.6%, less than 0.5%, less than 0.4%, lessthan 0.3%, less than 0.2%, less than 0.1%, less than 0.05%, less than0.01%, or less than 0.001%, by weight, or a range including any two ofthe aforementioned values, of acetic acid. In other variations, the SAPstream has less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10ppm, or a range including any two of the aforementioned values, ofacetic acid.

In some embodiments, the SAP is substantially free of stabilizers. Insome variations, the SAP stream has less than 5%, less than 4%, lessthan 3%, less than 2%, less than 1%, less than 0.9%, less than 0.8%,less than 0.7%, less than 0.6%, less than 0.5%, less than 0.4%, lessthan 0.3%, less than 0.2%, less than 0.1%, less than 0.05%, less than0.01%, or less than 0.001%, by weight, or a range including any two ofthe aforementioned values, of stabilizers. In other variations, the SAPstream has less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10ppm, or a range including any two of the aforementioned values, ofstabilizers.

In some embodiments, the SAP is substantially free of radicalpolymerization inhibitors. In some variations, the SAP stream has lessthan 5%, less than 4%, less than 3%, less than 2%, less than 1%, lessthan 0.9%, less than 0.8%, less than 0.7%, less than 0.6%, less than0.5%, less than 0.4%, less than 0.3%, less than 0.2%, less than 0.1%,less than 0.05%, less than 0.01%, or less than 0.001%, by weight, or arange including any two of the aforementioned values, of radicalpolymerization inhibitors. In other variations, the SAP stream has lessthan 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10 ppm, or a rangeincluding any two of the aforementioned values, of radicalpolymerization inhibitors.

In some embodiments, the SAP is substantially free of anti-foam agents.In some variations, the SAP stream has less than 5%, less than 4%, lessthan 3%, less than 2%, less than 1%, less than 0.9%, less than 0.8%,less than 0.7%, less than 0.6%, less than 0.5%, less than 0.4%, lessthan 0.3%, less than 0.2%, less than 0.1%, less than 0.05%, less than0.01%, or less than 0.001%, by weight, or a range including any two ofthe aforementioned values, of anti-foam agents. In other variations, theSAP stream has less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50ppm, 10 ppm, or a range including any two of the aforementioned values,of anti-foam agents.

In another aspect, an article is provided comprising any of the SAPprovided herein.

In certain embodiments, the article is a disposable diaper, trainingpants, adult incontinence undergarment, or sanitary napkins. In certainembodiments, the article is a disposable diaper.

Methods

With reference to FIG. 1, an exemplary process to produce PAA and SAPfrom ethylene is depicted. The process depicted involves ethyleneoxidation in step 100, carbonylation in step 200 to produce BPL and/orPPL, production of GAA in step 300, and production of PAA-SAP in step400. In step 100, ethylene is fed into an oxidative reactor to produceethylene oxide by an ethylene oxidation reaction. EO stream 110comprising EO exits the oxidative reaction zone of the oxidativereactor. In step 200, EO stream 110 is fed into a central reactor forthe conversion of EO and CO to BPL. In some variations, the entire EOstream 110 is fed into a central reactor. In other variations, a partialEO stream 110 is fed into a central reactor, e.g., to control the rateof EO entering the oxidative reactor. In step 200, EO stream 110comprising EO, from the oxidative reaction zone, enters the centralreactor as an inlet stream where it is combined with CO. Outlet streamscomprising either BPL (stream 210) or PPL (stream 220) exit the centralreactor.

In step 300, three alternatives are depicted to convert BPL and/or PPLto GAA using first, second (a), second (b) and third reactors. In onevariation, in step 300, BPL stream 210 is directly converted to GAA in afirst reactor. As depicted in FIG. 1, the central reactor may have anoutlet configured to output BPL stream 210 (top stream depicted inFIG. 1) comprising BPL, and BPL stream 210 enters the first reactor asan inlet stream where it is converted to GAA.

In another variation, in step 300, BPL stream 210 is converted to GAA ina two-reactor system. As depicted in FIG. 1, the central reactor mayhave an outlet configured to output BPL (middle stream depicted inFIG. 1) stream 210 comprising BPL, and BPL stream 210 enters the second(a) reactor as an inlet stream where it is converted to PPL. In second(a) reactor, BPL stream 210 is polymerized to produce PPL, and in second(b) reactor, the PPL is pyrolyzed to produce GAA. An outlet streamcomprising PPL, from the second (a) reactor, enters the second (b)reactor as an inlet stream where it is converted to GAA. In yet anothervariation, in step 300, PPL stream 220 is pyrolyzed to produce GAA. Asdepicted in FIG. 1, the central reactor may have an outlet configured tooutput PPL (bottom stream depicted in FIG. 1). PPL stream 220 comprisingPPL, from the central reactor, enters the third reactor as an inletstream where it is converted to GAA. First, second and third outletstreams comprising first, second and third GAA streams (collectivelyreferred to as GAA stream 310) exit the first, second (b) and thirdreactors. In step 400, GAA is converted to PAA and/or SAP in first,second and third reactors.

It should generally be understood that, in other variations of theprocess described in FIG. 1, one or more steps may be added or omitted.For example, in some variations, EO stream 110 from the oxidativereactor is further treated (e.g., dried and/or purified) before feedinginto the central reactor for the conversion of EO and CO to BPL in step200. In other variation, step 100 may be omitted, and ethylene oxideobtained from any commercially available source may be fed into thecentral reactor in step 200.

In another aspect, a method is provided for the conversion of ethyleneto polyacrylic acid (PAA), within an integrated system, the methodcomprising:

-   -   providing an inlet stream comprising ethylene to an oxidative        reactor of the integrated system to effect conversion of at        least a portion of the provided ethylene to EO,    -   providing an inlet stream comprising EO from the oxidative        reactor, and carbon monoxide (CO) to a central reactor of the        integrated system,    -   contacting the inlet stream with a metal carbonyl in a central        reaction zone to effect conversion of at least a portion of the        provided EO to a beta propiolactone (BPL),    -   directing an outlet stream comprising BPL from the central        reaction zone to at least one of:        -   (i) a first reactor, comprising an inlet fed by the outlet            stream comprising BPL of the central reactor, a first            reaction zone that converts at least some of the BPL to AA,            and an outlet from which an outlet stream comprising the AA            is obtainable,        -   (ii) a second (a) reactor, comprising an inlet fed by the            outlet stream comprising BPL of the central reactor, a            second (a) reaction zone that converts at least some of the            BPL to PPL, and an outlet from which an outlet stream            comprising the PPL is obtainable, and a second (b) reactor,            comprising an inlet fed by the outlet stream comprising PPL            of the second (a) reactor, a second (b) reaction zone that            converts at least some of the PPL to AA, and an outlet from            which an outlet stream comprising the AA is obtainable,        -   (iii) a third reactor, comprising an inlet fed by the outlet            stream comprising PPL of the central reactor, a third            reaction zone that converts at least some of the PPL to a            third product, and an outlet from which an outlet stream            comprising the AA is obtainable, and    -   obtaining AA; and    -   providing an outlet stream comprising AA from one or more of the        first, second (b) and third reactor, to the inlet of: (iv) a        fourth reactor in which at least some of the AA is converted to        polyacrylic acid (PAA), or a salt thereof.

In some variations, the AA is glacial AA (GAA).

In some embodiments, provided is a method for converting ethylene topolyacrylic acid (PAA), within an integrated system, the methodcomprising:

-   -   providing an inlet stream comprising ethylene to an oxidative        reactor of the integrated system to effect conversion of at        least a portion of the provided ethylene to EO,    -   providing an inlet stream comprising EO from the oxidative        reactor, and carbon monoxide (CO) to a central reactor of the        integrated system,    -   contacting the inlet stream with a metal carbonyl in a central        reaction zone to effect conversion of at least a portion of the        provided EO to a beta propiolactone (BPL) stream comprising BPL        and/or a polypropiolactone (PPL) outlet stream comprising PPL,    -   directing an outlet stream from the central reaction zone to at        least one of (i)-(iii):        -   (i) a first reactor, comprising an inlet fed by BPL from the            outlet stream of the central reactor, a first reaction zone            that converts at least some of the BPL to AA, and an outlet            from which an outlet stream comprising the AA is obtainable,        -   (ii) a second (a) reactor, comprising an inlet fed with BPL            from the outlet stream of the central reactor, a second (a)            reaction zone that converts at least some of the BPL to PPL,            and an outlet from which an outlet stream comprising the PPL            is obtainable, and a second (b) reactor, comprising an inlet            fed by the outlet stream comprising PPL of the second (a)            reactor, a second (b) reaction zone that converts at least            some of the PPL to AA, and an outlet from which an outlet            stream comprising the AA is obtainable,        -   (iii) a third reactor, comprising an inlet fed by PPL from            the PPL outlet stream of the central reactor, a third            reaction zone that converts at least some of the PPL to AA,            and an outlet from which an outlet stream comprising the AA            is obtainable, and    -   obtaining AA; and    -   providing an outlet stream comprising AA from one or more of the        first, second (b) and third reactor, to the inlet of: (iv) a        fourth reactor in which at least some of the AA is converted to        polyacrylic acid (PAA), or a salt thereof.

In one variation, the AA is glacial AA (GAA).

In some variations, provided is a method for converting ethylene topolyacrylic acid (PAA), within an integrated system, the methodcomprising:

providing an ethylene stream comprising ethylene to an oxidative reactorof the integrated system;

converting at least a portion of the ethylene in the ethylene stream toethylene oxide (EO) in the oxidative reactor to produce an EO streamcomprising the EO;

providing the EO stream from the oxidative reactor, and a carbonmonoxide (CO) stream comprising CO to a central reaction zone of theintegrated system;

contacting the EO stream and the CO stream with a metal carbonyl in thecentral reaction zone;

converting at least a portion of the EO in the EO stream to betapropiolactone (BPL) or polypropiolactone (PPL), or a combinationthereof, in the central reaction zone to produce a carbonylation streamcomprising BPL, or a carbonylation stream comprising PPL, or acombination thereof;

(i) directing the carbonylation stream comprising BPL to an AA reactor(also referred to in FIG. 1 as first reactor), and converting at leastsome of the BPL in the carbonylation stream to AA in the AA reactor toproduce an AA stream comprising the AA; or

(ii) directing the carbonylation stream comprising BPL to a PPL reactor(also referred to in FIG. 1 as second (a) reactor), converting at leastsome of the BPL in the carbonylation stream to PPL in the PPL reactor toproduce a PPL stream comprising PPL, directing the PPL stream to an AAreactor (also referred to in FIG. 1 as second (b) reactor), andconverting at least some of the PPL to AA in the AA reactor to producean AA stream; or

(iii) directing the carbonylation stream comprising PPL to an AA reactor(also referred to in FIG. 1 as third reactor), and converting at leastsome of the PPL in the carbonylation stream to AA in the AA reactor toproduce an AA stream comprising AA; or

any combinations of (i)-(iii) above;

directing the AA streams of (i)-(iii) above to a PAA reactor; and

converting at least a portion of the AA of the AA streams of (i)-(iii)above to polyacrylic acid (PAA), or a salt thereof, in the PAA reactor.

In certain variations, the method comprises (i). Thus, in somevariations, provided is a method for converting ethylene to polyacrylicacid (PAA), within an integrated system, comprising:

providing an ethylene stream comprising ethylene to an oxidative reactorof the integrated system;

converting at least a portion of the ethylene in the ethylene stream toethylene oxide (EO) in the oxidative reactor to produce an EO streamcomprising the EO;

providing the EO stream from the oxidative reactor, and a carbonmonoxide (CO) stream comprising CO to a central reaction zone of theintegrated system;

contacting the EO stream and the CO stream with a metal carbonyl in thecentral reaction zone;

converting at least a portion of the EO in the EO stream to betapropiolactone (BPL) in the central reaction zone to produce acarbonylation stream comprising BPL;

directing the carbonylation stream to an AA reactor (also referred to inFIG. 1 as first reactor);

converting at least some of the BPL of the carbonylation stream to AA inthe AA reactor to produce an AA stream comprising the AA;

directing AA from the AA stream to a PAA reactor (also referred to inFIG. 1 as fourth reactor); and

converting at least a portion of the AA of the AA stream to polyacrylicacid (PAA), or a salt thereof, in the PAA reactor.

In other variations, the method comprises (ii). Thus, in othervariations, provided is a method for converting ethylene to polyacrylicacid (PAA), within an integrated system, the method comprising:

providing an ethylene stream comprising ethylene to an oxidative reactorof the integrated system;

converting at least a portion of the ethylene in the ethylene stream toethylene oxide (EO) in the oxidative reactor to produce an EO streamcomprising the EO;

providing the EO stream from the oxidative reactor, and a carbonmonoxide (CO) stream comprising CO to a central reaction zone of theintegrated system;

contacting the EO stream and the CO stream with a metal carbonyl in thecentral reaction zone;

converting at least a portion of the EO in the EO stream to betapropiolactone (BPL) in the central reaction zone to produce acarbonylation stream comprising BPL;

directing the carbonylation stream to a PPL reactor (also referred to inFIG. 1 as second (a) reactor);

converting at least some of the BPL in the carbonylation stream to PPLin the PPL reactor to produce a PPL stream comprising the PPL;

directing PPL from the PPL stream to an AA reactor (also referred to inFIG. 1 as second (b) reactor);

converting at least some of the PPL in the PPL stream to AA in the AAreactor to produce an AA stream comprising the AA;

directing AA from the AA stream to a PAA reactor (also referred to inFIG. 1 as fourth reactor); and

converting at least a portion of the AA of the AA stream to polyacrylicacid (PAA), or a salt thereof, in the PAA reactor.

In yet other variations, the method comprises (iii). Thus, in yet othervariations, provided is a method for converting ethylene to polyacrylicacid (PAA), within an integrated system, the method comprising:

providing an ethylene stream comprising ethylene to an oxidative reactorof the integrated system;

converting at least a portion of the ethylene in the ethylene stream toethylene oxide (EO) in the oxidative reactor to produce an EO streamcomprising the EO;

providing the EO stream from the oxidative reactor, and a carbonmonoxide (CO) stream comprising CO to a central reaction zone of theintegrated system;

contacting the EO stream and the CO stream with a metal carbonyl in thecentral reaction zone;

converting at least a portion of the EO in the EO stream topolypropiolactone (PPL) in the central reaction zone to produce acarbonylation stream comprising PPL;

directing PPL from the carbonylation stream to an AA reactor (alsoreferred to in FIG. 1 as third reactor);

converting at least some of the PPL in the carbonylation stream to AA inthe AA reactor to produce an AA stream comprising the AA;

directing AA from the AA stream to a PAA reactor (also referred to inFIG. 1 as fourth reactor); and

converting at least a portion of the AA the AA stream to polyacrylicacid (PAA), or a salt thereof, in the PAA reactor.

In one embodiment, the method comprises (i) and (iii). Thus, in onevariation, provided is a method for converting ethylene to polyacrylicacid (PAA), within an integrated system, the method comprising:

providing an ethylene stream comprising ethylene to an oxidative reactorof the integrated system;

converting at least a portion of the ethylene in the ethylene stream toethylene oxide (EO) in the oxidative reactor to produce an EO streamcomprising the EO;

providing the EO stream from the oxidative reactor, and a carbonmonoxide (CO) stream comprising CO to a central reaction zone of theintegrated system;

contacting the EO stream and the CO stream with a metal carbonyl in thecentral reaction zone;

converting at least a portion of the EO in the EO stream to betapropiolactone (BPL) and polypropiolactone (PPL) in the central reactionzone to produce a first carbonylation stream comprising BPL and a secondcarbonylation stream comprising PPL;

directing BPL from the first carbonylation stream to a first AA reactor(also referred to in FIG. 1 as first reactor);

converting at least some of the BPL of the first carbonylation stream toAA in the first AA reactor to produce a first AA stream comprising theAA;

directing PPL from the second carbonylation stream to a second AAreactor (also referred to in FIG. 1 as third reactor);

converting at least some of the PPL of the second carbonylation streamto AA in the second AA reactor to produce a second AA stream comprisingthe AA;

directing AA from the first AA stream, the second AA stream, or acombination thereof, to a PAA reactor; and

converting at least a portion of the AA of the first AA stream, thesecond AA stream, or a combination thereof, to polyacrylic acid (PAA),or a salt thereof, in the PAA reactor.

In some variations of the foregoing method, the first and second AAreactors are the same reactor. In other variations, the first and secondAA reactors are separate reactors.

In some variations of the foregoing method where the first and second AAreactors are separate reactors, the PAA reactor is fed with AA from bothof the AA streams. For example, AA from the first AA stream and AA fromthe second AA stream may be combined at the PAA reactor, and in somevariations, this combination may occur either at the inlet of the PAAreactor or at a point prior to the PAA reactor inlet. In othervariations, the PAA is fed with AA exclusively from the first AA streamor exclusively from the second AA stream. In some variations the methodincludes controlling the ratio of the AA provided from the first AAstream and AA provided from the second AA stream or changing the ratioof the AA source fed to the PAA reactor over time.

In one embodiment, the method comprises (ii) and (iii). Thus, in onevariation, provided is a method for converting ethylene to polyacrylicacid (PAA), within an integrated system, the method comprising:

providing an ethylene stream comprising ethylene to an oxidative reactorof the integrated system;

converting at least a portion of the ethylene in the ethylene stream toethylene oxide (EO) in the oxidative reactor to produce an EO streamcomprising the EO;

providing the EO stream from the oxidative reactor, and a carbonmonoxide (CO) stream comprising CO to a central reaction zone of theintegrated system;

contacting the EO stream and the CO stream with a metal carbonyl in thecentral reaction zone;

converting at least a portion of the EO in the EO stream to betapropiolactone (BPL) and polypropiolactone (PPL) in the central reactionzone to produce a first carbonylation stream comprising BPL, and asecond carbonylation stream comprising PPL;

directing BPL from the first carbonylation stream to a PPL reactor (alsoreferred to in FIG. 1 as second (a) reactor);

converting at least some of the BPL of the first carbonylation stream toPPL in the PPL reactor to produce a PPL stream comprising the PPL;

directing PPL from the PPL stream to a first AA reactor (also referredto in FIG. 1 as second (b) reactor);

converting at least some of the PPL of the PPL stream to AA in the firstAA reactor to produce a first AA stream comprising the AA;

directing PPL from the second carbonylation stream to a second AAreactor (also referred to in FIG. 1 as third reactor);

converting at least some of the PPL of the second carbonylation streamto AA in the second AA reactor to produce a second AA stream comprisingthe AA;

directing AA from the first AA stream, the second AA stream, or acombination thereof, to a PAA reactor; and

converting at least a portion of the AA of the first AA stream, thesecond AA stream, or a combination thereof, to polyacrylic acid (PAA),or a salt thereof, in the PAA reactor.

In some variations of the foregoing method, the first and second AAreactors are the same reactor. In other variations, the first and secondAA reactors are separate reactors.

In some variations of the foregoing method, the PAA reactor isconfigured to receive AA from both of the AA streams. For example, thePAA reactor may be fed with AA from the first AA stream and AA from thesecond AA stream, and in some variations, the combination of AA from thetwo AA streams may occur either at the inlet of the PAA reactor or at apoint prior to the PAA reactor inlet. In other variations, the PAAreactor is fed with AA exclusively from the first AA stream orexclusively with AA from the second AA stream. In some variations themethod includes controlling the source of the AA provided to the PAAreactor and/or to controlling the ratio of AA supplied from the first AAstream and the second AA stream. In some variations, the method includeschanging the AA source or the ratio AA from the two sources over time.

In another embodiment, the method comprises (i) and (ii). Thus, in onevariation, provided is a method for converting ethylene to polyacrylicacid (PAA), within an integrated system, the method comprising:

providing an ethylene stream comprising ethylene to an oxidative reactorof the integrated system;

converting at least a portion of the ethylene in the ethylene stream toethylene oxide (EO) in the oxidative reactor to produce an EO streamcomprising the EO;

providing the EO stream from the oxidative reactor, and a carbonmonoxide (CO) stream comprising CO to a central reaction zone of theintegrated system;

contacting the EO stream and the CO stream with a metal carbonyl in thecentral reaction zone;

converting at least a portion of the EO in the EO stream to betapropiolactone (BPL) in the central reaction zone to produce acarbonylation stream comprising BPL;

directing at least a portion of the carbonylation stream to a first AAreactor (also referred to in FIG. 1 as first reactor);

converting at least some of the BPL of the carbonylation stream to AA inthe first AA reactor to produce a first AA stream comprising the AA;

directing at least a portion of the carbonylation stream to a PPLreactor (also referred to in FIG. 1 as second (a) reactor);

converting at least some of the BPL of the carbonylation stream to PPLin the PPL reactor to produce a PPL stream comprising the PPL;

directing PPL from the PPL stream to a second AA reactor (also referredto in FIG. 1 as second (b) reactor);

converting at least some of the PPL of the PPL stream to AA in thesecond AA reactor to produce a second AA stream comprising the AA;

directing AA from the first AA stream, AA from the second AA stream, ora combination thereof, to a PAA reactor; and

converting at least a portion of the AA of the first AA stream, thesecond AA stream, or a combination thereof, to polyacrylic acid (PAA),or a salt thereof, in the PAA reactor.

In some variations of the foregoing method, the first and second AAreactors are the same reactor. In other variations, the first and secondAA reactors are separate reactors.

In some variations of the foregoing method, the PAA reactor isconfigured to receive AA from both of the AA streams. For example, thePAA reactor may be fed with AA from the first AA stream and AA from thesecond AA stream, and in some variations, the combination of AA from thetwo AA streams may occur either at the inlet of the PAA reactor or at apoint prior to the PAA reactor inlet. In other variations, the PAAreactor is fed with AA exclusively from the first AA stream orexclusively with AA from the second AA stream. In some variations, themethod includes controlling the source of the AA provided to the PAAreactor and/or to controlling the ratio of AA supplied from the first AAstream and the second AA stream. In some variations, the method includeschanging the AA source or the ratio AA from the two sources over time.

In certain embodiments of the foregoing methods, the AA stream issubstantially free of an aldehyde impurity or a compound that derivesfrom the oxidation of propylene. In some embodiments, the AA issubstantially free of an aldehyde impurity. In some variations of themethods, the AA stream has less than 5%, less than 4%, less than 3%,less than 2%, less than 1%, less than 0.9%, less than 0.8%, less than0.7%, less than 0.6%, less than 0.5%, less than 0.4%, less than 0.3%,less than 0.2%, less than 0.1%, less than 0.05%, less than 0.01%, orless than 0.001%, by weight, or a range including any two of theaforementioned values, of an aldehyde impurity. In other variations, theAA stream has less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm,10 ppm, or a range including any two of the aforementioned values, of analdehyde impurity.

In other variations of the methods, the AA stream has less than 5%, lessthan 4%, less than 3%, less than 2%, less than 1%, less than 0.9%, lessthan 0.8%, less than 0.7%, less than 0.6%, less than 0.5%, less than0.4%, less than 0.3%, less than 0.2%, less than 0.1%, less than 0.05%,less than 0.01%, or less than 0.001%, by weight, or a range includingany two of the aforementioned values, of a compound that derives fromthe oxidation of propylene. In other variations, the AA stream has lessthan 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10 ppm, or a rangeincluding any two of the aforementioned values, of a compound thatderives from the oxidation of propylene.

In some embodiments, the AA is substantially free of furfural. In somevariations, the AA stream has less than 5%, less than 4%, less than 3%,less than 2%, less than 1%, less than 0.9%, less than 0.8%, less than0.7%, less than 0.6%, less than 0.5%, less than 0.4%, less than 0.3%,less than 0.2%, less than 0.1%, less than 0.05%, less than 0.01%, orless than 0.001%, by weight, or a range including any two of theaforementioned values, of furfural. In other variations, the AA streamhas less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10 ppm,or a range including any two of the aforementioned values, of furfural.

In some embodiments, the AA is substantially free of acetic acid. Insome variations, the AA stream has less than 5%, less than 4%, less than3%, less than 2%, less than 1%, less than 0.9%, less than 0.8%, lessthan 0.7%, less than 0.6%, less than 0.5%, less than 0.4%, less than0.3%, less than 0.2%, less than 0.1%, less than 0.05%, less than 0.01%,or less than 0.001%, by weight, or a range including any two of theaforementioned values, of acetic acid. In other variations, the AAstream has less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10ppm, or a range including any two of the aforementioned values, ofacetic acid.

In some embodiments, the AA is substantially free of stabilizers. Insome variations, the AA stream has less than 5%, less than 4%, less than3%, less than 2%, less than 1%, less than 0.9%, less than 0.8%, lessthan 0.7%, less than 0.6%, less than 0.5%, less than 0.4%, less than0.3%, less than 0.2%, less than 0.1%, less than 0.05%, less than 0.01%,or less than 0.001%, by weight, or a range including any two of theaforementioned values, of stabilizers. In other variations, the AAstream has less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10ppm, or a range including any two of the aforementioned values, ofstabilizers.

In some embodiments, the AA is substantially free of radicalpolymerization inhibitors. In some variations, the AA stream has lessthan 5%, less than 4%, less than 3%, less than 2%, less than 1%, lessthan 0.9%, less than 0.8%, less than 0.7%, less than 0.6%, less than0.5%, less than 0.4%, less than 0.3%, less than 0.2%, less than 0.1%,less than 0.05%, less than 0.01%, or less than 0.001%, by weight, or arange including any two of the aforementioned values, of radicalpolymerization inhibitors. In other variations, the AA stream has lessthan 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10 ppm, or a rangeincluding any two of the aforementioned values, of radicalpolymerization inhibitors.

In some embodiments, the AA is substantially free of anti-foam agents.In some variations, the AA stream has less than 5%, less than 4%, lessthan 3%, less than 2%, less than 1%, less than 0.9%, less than 0.8%,less than 0.7%, less than 0.6%, less than 0.5%, less than 0.4%, lessthan 0.3%, less than 0.2%, less than 0.1%, less than 0.05%, less than0.01%, or less than 0.001%, by weight, or a range including any two ofthe aforementioned values, of anti-foam agents. In other variations, theAA stream has less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm,10 ppm, or a range including any two of the aforementioned values, ofanti-foam agents.

In certain embodiments of the foregoing methods, the AA directed fromthe AA streams is glacial acrylic acid (GAA). In some variations, AA hasa purity of at least 98%, at least 98.5%, at least 99%, at least 99.1%,at least 99.2%, at least 99.3%, at least 99.4%, at least 99.5%, at least99.6%, at least 99.7%, at least 99.8%, or at least 99.9%; or between 99%and 99.95%, between 99.5% and 99.95%, between 99.6% and 99.95%, between99.7% and 99.95%, or between 99.8% and 99.95%.

In certain embodiments of the foregoing methods, the GAA issubstantially free of an aldehyde impurity or a compound that derivesfrom the oxidation of propylene. In some embodiments, the GAA issubstantially free of an aldehyde impurity. In some variations of theforegoing methods, the GAA stream has less than 5%, less than 4%, lessthan 3%, less than 2%, less than 1%, less than 0.9%, less than 0.8%,less than 0.7%, less than 0.6%, less than 0.5%, less than 0.4%, lessthan 0.3%, less than 0.2%, less than 0.1%, less than 0.05%, less than0.01%, or less than 0.001%, by weight, or a range including any two ofthe aforementioned values, of an aldehyde impurity. In other variations,the GAA stream has less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50ppm, 10 ppm, or a range including any two of the aforementioned values,of an aldehyde impurity.

In other variations of the methods, the GAA stream has less than 5%,less than 4%, less than 3%, less than 2%, less than 1%, less than 0.9%,less than 0.8%, less than 0.7%, less than 0.6%, less than 0.5%, lessthan 0.4%, less than 0.3%, less than 0.2%, less than 0.1%, less than0.05%, less than 0.01%, or less than 0.001%, by weight, or a rangeincluding any two of the aforementioned values, of a compound thatderives from the oxidation of propylene. In other variations, the GAAstream has less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10ppm, or a range including any two of the aforementioned values, of acompound that derives from the oxidation of propylene.

In some embodiments, the GAA is substantially free of furfural. In somevariations, the GAA stream has less than 5%, less than 4%, less than 3%,less than 2%, less than 1%, less than 0.9%, less than 0.8%, less than0.7%, less than 0.6%, less than 0.5%, less than 0.4%, less than 0.3%,less than 0.2%, less than 0.1%, less than 0.05%, less than 0.01%, orless than 0.001%, by weight, or a range including any two of theaforementioned values, of furfural. In other variations, the GAA streamhas less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10 ppm,or a range including any two of the aforementioned values, of furfural.

In some embodiments, the GAA is substantially free of acetic acid. Insome variations, the GAA stream has less than 5%, less than 4%, lessthan 3%, less than 2%, less than 1%, less than 0.9%, less than 0.8%,less than 0.7%, less than 0.6%, less than 0.5%, less than 0.4%, lessthan 0.3%, less than 0.2%, less than 0.1%, less than 0.05%, less than0.01%, or less than 0.001%, by weight, or a range including any two ofthe aforementioned values, of acetic acid. In other variations, the GAAstream has less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10ppm, or a range including any two of the aforementioned values, ofacetic acid.

In some embodiments, the GAA is substantially free of stabilizers. Insome variations, the GAA stream has less than 5%, less than 4%, lessthan 3%, less than 2%, less than 1%, less than 0.9%, less than 0.8%,less than 0.7%, less than 0.6%, less than 0.5%, less than 0.4%, lessthan 0.3%, less than 0.2%, less than 0.1%, less than 0.05%, less than0.01%, or less than 0.001%, by weight, or a range including any two ofthe aforementioned values, of stabilizers. In other variations, the GAAstream has less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10ppm, or a range including any two of the aforementioned values, ofstabilizers.

In some embodiments, the GAA is substantially free of radicalpolymerization inhibitors. In some variations, the GAA stream has lessthan 5%, less than 4%, less than 3%, less than 2%, less than 1%, lessthan 0.9%, less than 0.8%, less than 0.7%, less than 0.6%, less than0.5%, less than 0.4%, less than 0.3%, less than 0.2%, less than 0.1%,less than 0.05%, less than 0.01%, or less than 0.001%, by weight, or arange including any two of the aforementioned values, of radicalpolymerization inhibitors. In other variations, the GAA stream has lessthan 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10 ppm, or a rangeincluding any two of the aforementioned values, of radicalpolymerization inhibitors.

In some embodiments, the GAA is substantially free of anti-foam agents.In some variations, the GAA stream has less than 5%, less than 4%, lessthan 3%, less than 2%, less than 1%, less than 0.9%, less than 0.8%,less than 0.7%, less than 0.6%, less than 0.5%, less than 0.4%, lessthan 0.3%, less than 0.2%, less than 0.1%, less than 0.05%, less than0.01%, or less than 0.001%, by weight, or a range including any two ofthe aforementioned values, of anti-foam agents. In other variations, theGAA stream has less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50ppm, 10 ppm, or a range including any two of the aforementioned values,of anti-foam agents.

In certain embodiments of the foregoing methods, the PAA, or a saltthereof, is substantially free of an aldehyde impurity or a compoundthat derives from the oxidation of propylene. In some embodiments, thePAA is substantially free of an aldehyde impurity. In some embodiments,the PAA stream is substantially free of an aldehyde impurity. In somevariations, the AA outlet stream has less than 5%, less than 4%, lessthan 3%, less than 2%, less than 1%, less than 0.9%, less than 0.8%,less than 0.7%, less than 0.6%, less than 0.5%, less than 0.4%, lessthan 0.3%, less than 0.2%, less than 0.1%, less than 0.05%, less than0.01%, or less than 0.001%, by weight, or a range including any two ofthe aforementioned values, of an aldehyde impurity. In other variations,the PAA stream has less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50ppm, 10 ppm, or a range including any two of the aforementioned values,of an aldehyde impurity.

In other variations of the methods, the PAA stream has less than 5%,less than 4%, less than 3%, less than 2%, less than 1%, less than 0.9%,less than 0.8%, less than 0.7%, less than 0.6%, less than 0.5%, lessthan 0.4%, less than 0.3%, less than 0.2%, less than 0.1%, less than0.05%, less than 0.01%, or less than 0.001%, by weight, or a rangeincluding any two of the aforementioned values, of a compound thatderives from the oxidation of propylene. In other variations, the PAAstream has less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10ppm, or a range including any two of the aforementioned values, of acompound that derives from the oxidation of propylene.

In some embodiments, the PAA is substantially free of furfural. In somevariations, the PAA stream has less than 5%, less than 4%, less than 3%,less than 2%, less than 1%, less than 0.9%, less than 0.8%, less than0.7%, less than 0.6%, less than 0.5%, less than 0.4%, less than 0.3%,less than 0.2%, less than 0.1%, less than 0.05%, less than 0.01%, orless than 0.001%, by weight, or a range including any two of theaforementioned values, of furfural. In other variations, the PAA streamhas less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10 ppm,or a range including any two of the aforementioned values, of furfural.

In some embodiments, the PAA is substantially free of acetic acid. Insome variations, the PAA stream has less than 5%, less than 4%, lessthan 3%, less than 2%, less than 1%, less than 0.9%, less than 0.8%,less than 0.7%, less than 0.6%, less than 0.5%, less than 0.4%, lessthan 0.3%, less than 0.2%, less than 0.1%, less than 0.05%, less than0.01%, or less than 0.001%, by weight, or a range including any two ofthe aforementioned values, of acetic acid. In other variations, the PAAstream has less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10ppm, or a range including any two of the aforementioned values, ofacetic acid.

In some embodiments, the PAA is substantially free of stabilizers. Insome variations, the PAA stream has less than 5%, less than 4%, lessthan 3%, less than 2%, less than 1%, less than 0.9%, less than 0.8%,less than 0.7%, less than 0.6%, less than 0.5%, less than 0.4%, lessthan 0.3%, less than 0.2%, less than 0.1%, less than 0.05%, less than0.01%, or less than 0.001%, by weight, or a range including any two ofthe aforementioned values, of stabilizers. In other variations, the PAAstream has less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10ppm, or a range including any two of the aforementioned values, ofstabilizers.

In some embodiments, the PAA is substantially free of radicalpolymerization inhibitors. In some variations, the PAA stream has lessthan 5%, less than 4%, less than 3%, less than 2%, less than 1%, lessthan 0.9%, less than 0.8%, less than 0.7%, less than 0.6%, less than0.5%, less than 0.4%, less than 0.3%, less than 0.2%, less than 0.1%,less than 0.05%, less than 0.01%, or less than 0.001%, by weight, or arange including any two of the aforementioned values, of radicalpolymerization inhibitors. In other variations, the PAA stream has lessthan 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10 ppm, or a rangeincluding any two of the aforementioned values, of radicalpolymerization inhibitors.

In some embodiments, the PAA is substantially free of anti-foam agents.In some variations, the PAA stream has less than 5%, less than 4%, lessthan 3%, less than 2%, less than 1%, less than 0.9%, less than 0.8%,less than 0.7%, less than 0.6%, less than 0.5%, less than 0.4%, lessthan 0.3%, less than 0.2%, less than 0.1%, less than 0.05%, less than0.01%, or less than 0.001%, by weight, or a range including any two ofthe aforementioned values, of anti-foam agents. In other variations, thePAA stream has less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50ppm, 10 ppm, or a range including any two of the aforementioned values,of anti-foam agents.

In certain embodiments, the PAA, or a salt thereof, is formulated foruse in compositions for paper treatment, water treatment, or detergentco-builder applications.

In certain embodiments, the method further comprises:

-   -   providing PAA from an outlet stream comprising PAA, or a salt        thereof, from the fourth reactor, to the inlet of: (v) a fifth        reactor in which at least some of the PAA, or a salt thereof, is        converted to superabsorbent polymer (SAP).

In some variations, the method further comprises:

providing a PAA stream comprising PAA, or a salt thereof, from the PAAreactor;

directing PAA from the PAA stream to a superabsorbent polymer (SAP)reactor; and

converting at least a portion of the PAA in the PAA stream to SAP in theSAP reactor.

In certain embodiments of the foregoing method, the SAP comprises lessthan about 1000 parts per million residual monoethylenically unsaturatedmonomer. In certain embodiments, the SAP is substantially free of analdehyde impurity or a compound that derives from the oxidation ofpropylene. In some embodiments, the SAP is substantially free of analdehyde impurity. In some variations, the SAP stream has less than 5%,less than 4%, less than 3%, less than 2%, less than 1%, less than 0.9%,less than 0.8%, less than 0.7%, less than 0.6%, less than 0.5%, lessthan 0.4%, less than 0.3%, less than 0.2%, less than 0.1%, less than0.05%, less than 0.01%, or less than 0.001%, by weight, or a rangeincluding any two of the aforementioned values, of an aldehyde impurity.In other variations, the SAP stream has less than 10,000 ppm, 1,000 ppm,500 ppm, 100 ppm, 50 ppm, 10 ppm, or a range including any two of theaforementioned values, of an aldehyde impurity.

In other variations of the methods, the SAP stream has less than 5%,less than 4%, less than 3%, less than 2%, less than 1%, less than 0.9%,less than 0.8%, less than 0.7%, less than 0.6%, less than 0.5%, lessthan 0.4%, less than 0.3%, less than 0.2%, less than 0.1%, less than0.05%, less than 0.01%, or less than 0.001%, by weight, or a rangeincluding any two of the aforementioned values, of a compound thatderives from the oxidation of propylene. In other variations, the SAPstream has less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10ppm, or a range including any two of the aforementioned values, of acompound that derives from the oxidation of propylene.

In some embodiments, the SAP is substantially free of furfural. In somevariations, the SAP stream has less than 5%, less than 4%, less than 3%,less than 2%, less than 1%, less than 0.9%, less than 0.8%, less than0.7%, less than 0.6%, less than 0.5%, less than 0.4%, less than 0.3%,less than 0.2%, less than 0.1%, less than 0.05%, less than 0.01%, orless than 0.001%, by weight, or a range including any two of theaforementioned values, of furfural. In other variations, the SAP streamhas less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10 ppm,or a range including any two of the aforementioned values, of furfural.

In some embodiments, the SAP is substantially free of acetic acid. Insome variations, the SAP stream has less than 5%, less than 4%, lessthan 3%, less than 2%, less than 1%, less than 0.9%, less than 0.8%,less than 0.7%, less than 0.6%, less than 0.5%, less than 0.4%, lessthan 0.3%, less than 0.2%, less than 0.1%, less than 0.05%, less than0.01%, or less than 0.001%, by weight, or a range including any two ofthe aforementioned values, of acetic acid. In other variations, the SAPstream has less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10ppm, or a range including any two of the aforementioned values, ofacetic acid.

In some embodiments, the SAP is substantially free of stabilizers. Insome variations, the SAP stream has less than 5%, less than 4%, lessthan 3%, less than 2%, less than 1%, less than 0.9%, less than 0.8%,less than 0.7%, less than 0.6%, less than 0.5%, less than 0.4%, lessthan 0.3%, less than 0.2%, less than 0.1%, less than 0.05%, less than0.01%, or less than 0.001%, by weight, or a range including any two ofthe aforementioned values, of stabilizers. In other variations, the SAPstream has less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10ppm, or a range including any two of the aforementioned values, ofstabilizers.

In some embodiments, the SAP is substantially free of radicalpolymerization inhibitors. In some variations, the SAP stream has lessthan 5%, less than 4%, less than 3%, less than 2%, less than 1%, lessthan 0.9%, less than 0.8%, less than 0.7%, less than 0.6%, less than0.5%, less than 0.4%, less than 0.3%, less than 0.2%, less than 0.1%,less than 0.05%, less than 0.01%, or less than 0.001%, by weight, or arange including any two of the aforementioned values, of radicalpolymerization inhibitors. In other variations, the SAP stream has lessthan 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10 ppm, or a rangeincluding any two of the aforementioned values, of radicalpolymerization inhibitors.

In some embodiments, the SAP is substantially free of anti-foam agents.In some variations, the SAP stream has less than 5%, less than 4%, lessthan 3%, less than 2%, less than 1%, less than 0.9%, less than 0.8%,less than 0.7%, less than 0.6%, less than 0.5%, less than 0.4%, lessthan 0.3%, less than 0.2%, less than 0.1%, less than 0.05%, less than0.01%, or less than 0.001%, by weight, or a range including any two ofthe aforementioned values, of anti-foam agents. In other variations, theSAP stream has less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50ppm, 10 ppm, or a range including any two of the aforementioned values,of anti-foam agents.

In some embodiments of the foregoing method, the GAA is converted to PAAless than two weeks after the ethylene is converted to EO. In someembodiments, GAA is converted to PAA less than one week after theethylene is converted to EO. In some embodiments, GAA is converted toPAA less than six, five, four, three, two days after the ethylene isconverted to EO. In some embodiments, GAA is converted to PAA less than24 hours after the ethylene is converted to EO.

The sections below more fully describe elements of the integrated systemand methods as well as some of the reactions and conditions foreffecting the conversion of ethylene to PAA and to SAP.

Controller

The controller can be any integrated means (e.g., a computer-basednetwork) to monitor, control and/or modulate (e.g., increase, decreaseor maintain) all processes and components related to the disclosedsystem, including all reaction zones (via sensors, switches, valves,vacuum, pumps etc.). The controller can independently modulateproduction of the BPL by the central reactor, production of the EO in anoxidative reactor, if present, and production for each of the BPL, PPL,AA, PAA, and SAP products, in their respective reactors, by, e.g.,independently controlling temperatures and pressures in each reactionzone and flow rates for inlet and outlet streams.

In some embodiments, the controller is used to independently increase,decrease or maintain production of the EO, BPL, PPL, AA, PAA, or a saltthereof, and SAP by respective reactors within the integrated system.

Ethylene to EO

The disclosed system optionally further includes, at its upstream end,an oxidative reactor that produces EO on-site and provides EO to thecentral reactor. In certain embodiments, EO is obtained directly fromthe gas phase oxidation of ethylene. This embodiment is advantageous inthat it avoids the need to isolate, store, and transport ethylene oxidewhich is both toxic and explosive. In certain embodiments, the ethyleneoxide is maintained in the gas phase as produced and fed to the centralreactor without condensing it to a liquid.

Another benefit of producing EO on-site includes a considerable increasein the plant's capacity to produce greater quantities of C₃ and/or C₄products. In certain embodiments, the system can produce any combinationof C₃ and/or C₄ products at a rate of about 200, 250, 300, 350, 400,450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1,000 kilotonsper annum (kta), or within a range including any two of these values.

Thus, in certain embodiments, the system further comprises an oxidativereactor, comprising an inlet fed by ethylene, an oxidative reaction zonethat converts at least some of the ethylene to EO, and an outlet whichprovides an outlet stream comprising the EO, which is fed to the inletof the central reactor.

Alternatively, in other embodiments, EO is not produced within thedisclosed system. Rather, in such embodiments, an upstream oxidativereactor is absent and the central reactor is fed EO that was producedoff-site.

EO to BPL

In certain embodiments, the disclosed system includes a central reactorfor carbonylation of EO into BPL via a “carbonylation reaction.” Thecentral reactor receives the EO (e.g., from the EO source) and CO (e.g.,from the CO source), as well as the carbonylation catalyst and solvents,etc. and carries out the carbonylation reaction of the EO in the centralreaction zone. In certain embodiments, the EO and CO are received atseparate inputs. In certain embodiments, the EO and CO are received as amixture. In certain embodiments, the EO/CO mixture received is gaseous.In certain embodiments, the carbonylation reaction is continuous. Suchcontinuous carbonylation reactions can be conducted in a continuousstirred tank reactor or a plug flow reactor such that BPL solution iswithdrawn at essentially the same rate it is formed.

In certain embodiments, the carbonylation reaction of EO to BPL proceedsas shown below:

Carbonylation Reaction Conditions

Methods of making BPL are known in the art and include those describedin WO2013/063191 and WO2014/004858. Suitable catalysts and reactionconditions for effecting the above reactions are described herein andalso disclosed in published PCT applications: WO2003/050154,WO2004/089923, WO2012/158573, WO2010/118128, WO2013/063191, andWO2014/008232; in U.S. Pat. Nos. 5,359,081 and 5,310,948 and in thepublication “Synthesis of beta-Lactones” J. Am. Chem. Soc., vol. 124,2002, pages 1174-1175.

In certain embodiments, the central reactor, comprising an inlet, is fedby a “reaction stream” comprising EO and CO. In certain embodiments, thereaction stream fed into the carbonylation reaction comprises a gaseousmixture containing EO and CO. In certain embodiments, the molar ratio ofCO to EO in the reaction stream ranges from about 1:1 to about 10,000:1.In certain embodiments, the molar ratio of CO to EO in the reactionstream is about 5000:1, is about 2500:1, is about 2000:1, is about1500:1, is about 1000:1, is about 500:1, is about 1:500, is about 200:1,is about 100:1, is about 50:1, is about 20:1, is about 10:1, is about5:1 or is about 1:1, or within a range including any two of theseratios.

In certain embodiments, the reaction stream further comprises one ormore additional components. In certain embodiments, the additionalcomponents comprise diluents which do not directly participate in thechemical reactions of EO. In certain embodiments, such diluents mayinclude one or more inert gases (e.g., nitrogen, argon, helium and thelike) or volatile organic molecules such as hydrocarbons, ethers, andthe like. In certain embodiments, the reaction stream may comprisehydrogen, traces of carbon dioxide, methane, and other compoundscommonly found in industrial CO streams. In certain embodiments, thefeed stream may further comprise materials that may have a direct orindirect chemical function in one or more of the processes involved inthe conversion of EO to BPL and various end products. Additionalreactants can also include mixtures of CO and another gas. For example,as noted above, In certain embodiments, CO is provided in a mixture withhydrogen (e.g., Syngas).

In certain embodiments, the reaction stream is characterized in that itis essentially free of oxygen. In certain embodiments, the reactionstream is characterized in that it is essentially free of water. Incertain embodiments, the reaction stream is characterized in that it isessentially free of oxygen and water.

Carbonylation Solvents

In certain embodiments, the carbonylation reaction described herein isperformed in a solvent. In certain embodiments, the solvent is fed tothe central reaction zone as a separate stream. In other embodiments,the solvent may be fed to the central reaction zone along with thecatalyst, EO or another feed stream entering the carbonylation reactionin the central reaction zone. In certain embodiments, the solvent entersthe central reaction zone along with the carbonylation catalyst which isprovided as a catalyst solution in the solvent. In certain embodiments,the solvent enters the central reaction zone in two or more separatefeed streams. In embodiments where solvent is present in the centralreaction zone, it may also be present in the carbonylation outletstream.

The solvent may be selected from any solvent, and mixtures of solvents.Additionally, BPL may be utilized as a co-solvent. Solvents mostsuitable for the methods include ethers, hydrocarbons and non proticpolar solvents. Suitable solvents include, for example, tetrahydrofuran(“THF”), sulfolane, N-methyl pyrrolidone, 1,3dimethyl-2-imidazolidinone, diglyme, triglyme, tetraglyme, diethyleneglycol dibutyl ether, isosorbide ethers, methyl tertbutyl ether,diethylether, diphenyl ether, 1,4-dioxane, ethylene carbonate, propylenecarbonate, butylene carbonate, dibasic esters, diethyl ether,acetonitrile, ethyl acetate, dimethoxy ethane, acetone, and methylethylketone.

In certain embodiments, the carbonylation reaction further includes aLewis base additive to the carbonylation reaction in the centralreaction zone. In some embodiments such Lewis base additives canstabilize or reduce deactivation of the catalysts. In certainembodiments, the Lewis base additive is selected from the groupconsisting of phosphines, amines, guanidines, amidines, andnitrogen-containing heterocycles. In certain embodiments, the Lewis baseadditive is a phosphine. In certain embodiments, the Lewis base additiveis a hindered amine base. In certain embodiments, the Lewis baseadditive is a 2,6-lutidine; imidazole, 1-methylimidazole,4-dimethylaminopyridine, trihexylamine and triphenylphosphine.

Carbonylation Catalysts

Numerous carbonylation catalysts known in the art are suitable for (orcan be adapted to) methods described herein. For example, in someembodiments, the carbonylation methods utilize a metal carbonyl-Lewisacid catalyst such as those described in U.S. Pat. No. 6,852,865. Inother embodiments, the carbonylation is performed with one or more ofthe carbonylation catalysts disclosed in U.S. patent application Ser.No. 10/820,958; and Ser. No. 10/586,826. In other embodiments, thecarbonylation is performed with one or more of the catalysts disclosedin U.S. Pat. Nos. 5,310,948; 7,420,064; and 5,359,081. Additionalcatalysts for the carbonylation of epoxides are discussed in a review inChem. Commun., 2007, 657-674.

In some embodiments, the carbonylation catalyst includes a metalcarbonyl compound. Typically, in one variation, a single metal carbonylcompound is provided, but in some embodiments, mixtures of two or moremetal carbonyl compounds are provided. Thus, when a provided metalcarbonyl compound “comprises”, e.g., a neutral metal carbonyl compound,it is understood that the provided metal carbonyl compound can be asingle neutral metal carbonyl compound, or a neutral metal carbonylcompound in combination with one or more metal carbonyl compounds.Preferably, the provided metal carbonyl compound is capable ofring-opening an epoxide and facilitating the insertion of CO into theresulting metal carbon bond. Metal carbonyl compounds with thisreactivity are well known in the art and are used for laboratoryexperimentation as well as in industrial processes such ashydroformylation.

In some embodiments, the metal carbonyl compound comprises an anionicmetal carbonyl moiety. In other embodiments, the metal carbonyl compoundcomprises a neutral metal carbonyl compound. In some embodiments, themetal carbonyl compound comprises a metal carbonyl hydride or a hydridometal carbonyl compound. In some embodiments, the metal carbonylcompound acts as a pre-catalyst which reacts in situ with one or morereaction components to provide an active species different from thecompound initially provided. Such pre-catalysts are specificallyencompassed as it is recognized that the active species in a givenreaction may not be known with certainty; thus the identification ofsuch a reactive species in situ does not itself depart from the spiritor teachings herein.

In some embodiments, the metal carbonyl compound comprises an anionicmetal carbonyl species. In some embodiments, such anionic metal carbonylspecies have the general formula [Q_(d)M′_(e)(CO)_(w)]^(y−), where Q isany ligand and need not be present, M′ is a metal atom, d is an integerbetween 0 and 8 inclusive, e is an integer between 1 and 6 inclusive, wis a number such as to provide the stable anionic metal carbonylcomplex, and y is the charge of the anionic metal carbonyl species. Insome embodiments, the anionic metal carbonyl has the general formula[QM′(CO)_(w)]^(y−), where Q is any ligand and need not be present, M′ isa metal atom, w is a number such as to provide the stable anionic metalcarbonyl, and y is the charge of the anionic metal carbonyl.

In some embodiments, the anionic metal carbonyl species includemonoanionic carbonyl complexes of metals from groups 5, 7 or 9 of theperiodic table or dianionic carbonyl complexes of metals from groups 4or 8 of the periodic table. In some embodiments, the anionic metalcarbonyl compound contains cobalt or manganese. In some embodiments, theanionic metal carbonyl compound contains rhodium. Suitable anionic metalcarbonyl compounds include, for example, [Co(CO)₄]⁻, [Ti(CO)₆]²⁻,[V(CO)₆]⁻, [Rh(CO)₄]⁻, [Fe(CO)₄]²⁻, [Ru(CO)₄]²⁻, [Os(CO)₄]²⁻,[Cr₂(CO)₁₀]²⁻, [Fe₂(CO)₈]²⁻, [Tc(CO)₅]⁻, [Re(CO)₅]⁻, and [Mn(CO)₅]⁻. Insome embodiments, the anionic metal carbonyl comprises [Co(CO)₄]⁻. Insome embodiments, a mixture of two or more anionic metal carbonylcomplexes may be present in the carbonylation catalysts used in themethods.

The term “such as to provide a stable anionic metal carbonyl” for[Q_(d)M′_(e)(CO)_(w)]^(y−) is used herein to mean that[Q_(d)M′_(e)(CO)_(w)]^(y−) is a species that may be characterized byanalytical means, e.g., NMR, IR, X-ray crystallography, Ramanspectroscopy and/or electron spin resonance (EPR) and isolable incatalyst form in the presence of a suitable cation or a species formedin situ. It is to be understood that metals which can form stable metalcarbonyl complexes have known coordinative capacities and propensitiesto form polynuclear complexes which, together with the number andcharacter of optional ligands Q that may be present and the charge onthe complex will determine the number of sites available for CO tocoordinate and therefore the value of w. Typically, such compoundsconform to the “18-electron rule”. Such knowledge is within the grasp ofone having ordinary skill in the arts pertaining to the synthesis andcharacterization of metal carbonyl compounds.

In embodiments where the provided metal carbonyl compound is an anionicspecies, one or more cations must also necessarily be present. Noparticular constraints are placed on the identity of such cations. Insome embodiments, the cation associated with an anionic metal carbonylcompound comprises a reaction component of another category describedherein below. For example, in some embodiments, the metal carbonyl anionis associated with a cationic Lewis acid. In other embodiments a cationassociated with a provided anionic metal carbonyl compound is a simplemetal cation such as those from Groups 1 or 2 of the periodic table(e.g., Na⁺, Li⁺, K⁺, and Mg²⁺). In other embodiments a cation associatedwith a provided anionic metal carbonyl compound is a bulky nonelectrophilic cation such as an ‘onium salt’ (e.g., Bu₄N⁺, PPN⁺, Ph₄P⁺,and Ph₄As⁺). In other embodiments, a metal carbonyl anion is associatedwith a protonated nitrogen compound (e.g., a cation may comprise acompound such as MeTBD-H⁺, DMAP-H⁺, DABCO-H⁺, and DBU-H⁺). In someembodiments, compounds comprising such protonated nitrogen compounds areprovided as the reaction product between an acidic hydrido metalcarbonyl compound and a basic nitrogen-containing compound (e.g., amixture of DBU and HCo(CO)₄).

In some embodiments, a catalyst utilized in the methods described hereincomprises a neutral metal carbonyl compound. In some embodiments, suchneutral metal carbonyl compounds have the general formulaQ_(d)M′_(e)(CO)_(w′), where Q is any ligand and need not be present, M′is a metal atom, d is an integer between 0 and 8 inclusive, e is aninteger between 1 and 6 inclusive, and w′ is a number such as to providethe stable neutral metal carbonyl complex. In some embodiments, theneutral metal carbonyl has the general formula QM′(CO)_(w′). In someembodiments, the neutral metal carbonyl has the general formulaM′(CO)_(w′). In some embodiments, the neutral metal carbonyl has thegeneral formula QM′₂(CO)_(w′). In some embodiments, the neutral metalcarbonyl has the general formula M′₂(CO)_(w′). Suitable neutral metalcarbonyl compounds include, for example, Ti(CO)₇, V₂(CO)₁₂, Cr(CO)₆,Mo(CO)₆, W(CO)₆, Mn₂(CO)₁₀, Tc₂(CO)₁₀, Re₂(CO)₁₀, Fe(CO)₅, Ru(CO)₅,Os(CO)₅, Ru₃(CO)₁₂, Os₃(CO)₁₂ Fe₃(CO)₁₂, Fe₂(CO)₉, Co₄(CO)₁₂, Rh₄(CO)₁₂,Rh₆(CO)₁₆, Ir₄(CO)₁₂, Co₂(CO)₈, and Ni(CO)₄. The term “such as toprovide a stable neutral metal carbonyl” for Q_(d)M′_(e)(CO)_(w′) isused herein to mean that Q_(d)M′_(e)(CO)_(w′) is a species that may becharacterized by analytical means, e.g., NMR, IR, X-ray crystallography,Raman spectroscopy and/or electron spin resonance (EPR) and isolable inpure form or a species formed in situ. It is to be understood thatmetals which can form stable metal carbonyl complexes have knowncoordinative capacities and propensities to form polynuclear complexeswhich, together with the number and character of optional ligands Q thatmay be present will determine the number of sites available for CO tocoordinate and therefore the value of w′. Typically, such compoundsconform to stoichiometries conforming to the “18-electron rule”. Suchknowledge is within the grasp of one having ordinary skill in the artspertaining to the synthesis and characterization of metal carbonylcompounds.

In some embodiments, no ligands Q are present on the metal carbonylcompound. In other embodiments, one or more ligands Q are present on themetal carbonyl compound. In some embodiments, where Q is present, eachoccurrence of Q is selected from the group consisting of phosphineligands, amine ligands, cyclopentadienyl ligands, heterocyclic ligands,nitriles, phenols, and combinations of two or more of these. In someembodiments, one or more of the CO ligands of any of the metal carbonylcompounds described above is replaced with a ligand Q. In someembodiments, Q is a phosphine ligand. In some embodiments, Q is atriaryl phosphine. In some embodiments, Q is trialkyl phosphine. In someembodiments, Q is a phosphite ligand. In some embodiments, Q is anoptionally substituted cyclopentadienyl ligand. In some embodiments, Qis cp. In some embodiments, Q is cp*. In some embodiments, Q is an amineor a heterocycle.

In some embodiments, the carbonylation catalyst utilized in the methodsdescribed above further includes a Lewis acidic component. In someembodiments, the carbonylation catalyst includes an anionic metalcarbonyl complex and a cationic Lewis acidic component. In someembodiments, the metal carbonyl complex includes a carbonyl cobaltateand the Lewis acidic co-catalyst includes a metal-centered cationicLewis acid. In some embodiments, an included Lewis acid comprises aboron compound.

In some embodiments, where an included Lewis acid comprises a boroncompound, the boron compound comprises a trialkyl boron compound or atriaryl boron compound. In some embodiments, an included boron compoundcomprises one or more boron-halogen bonds. In some embodiments, where anincluded boron compound comprises one or more boron-halogen bonds, thecompound is a dialkyl halo boron compound (e.g., R₂BX), a dihalomonoalkyl compound (e.g., RBX₂), an aryl halo boron compound (e.g.,Ar₂BX or ArBX₂), or a trihalo boron compound (e.g., BCl₃ or BBr₃),wherein each R is an alkyl group; each X is a halogen; and each Ar is anaromatic group.

In some embodiments, where the included Lewis acid comprises ametal-centered cationic Lewis acid, the Lewis acid is a cationic metalcomplex. In some embodiments, the cationic metal complex has its chargebalanced either in part, or wholly by one or more anionic metal carbonylmoieties. Suitable anionic metal carbonyl compounds include thosedescribed above. In some embodiments, there are 1 to 17 such anionicmetal carbonyls balancing the charge of the metal complex. In someembodiments, there are 1 to 9 such anionic metal carbonyls balancing thecharge of the metal complex. In some embodiments, there are 1 to 5 suchanionic metal carbonyls balancing the charge of the metal complex. Insome embodiments, there are 1 to 3 such anionic metal carbonylsbalancing the charge of the metal complex.

In some embodiments, where carbonylation catalysts used in methodsdescribed herein include a cationic metal complex, the metal complex hasthe formula [(L^(c))_(v)M_(b)]^(z+), where:

-   -   L^(c) is a ligand where, when two or more L^(c) are present,        each may be the same or different;    -   M is a metal atom where, when two M are present, each may be the        same or different;    -   v is an integer from 1 to 4 inclusive;    -   b is an integer from 1 to 2 inclusive; and    -   z is an integer greater than 0 that represents the cationic        charge on the metal complex.

In some embodiments, provided Lewis acids conform to structure I:

wherein:

-   -   is a multidentate ligand;    -   M is a metal atom coordinated to the multidentate ligand; and    -   a is the charge of the metal atom and ranges from 0 to 2.

In some embodiments, provided metal complexes conform to structure II:

wherein a is as defined above (each a may be the same or different), and

-   -   M¹ is a first metal atom;    -   M² is a second metal atom; and    -   comprises a multidentate ligand system capable of coordinating        both metal atoms.

For sake of clarity, and to avoid confusion between the net and totalcharge of the metal atoms in complexes I and II and other structuresherein, the charge (a⁺) shown on the metal atom in complexes I and IIabove represents the net charge on the metal atom after it has satisfiedany anionic sites of the multidentate ligand. For example, if a metalatom in a complex of formula I were Cr(III), and the ligand wereporphyrin (a tetradentate ligand with a charge of −2), then the chromiumatom would have a net charge of +1, and a would be 1.

Suitable multidentate ligands include, for example, porphyrin ligands 1,salen ligands 2, dibenzotetramethyltetraaza[14]annulene (tmtaa) ligands3, phthalocyaninate ligands 4, the Trost ligand 5, tetraphenylporphyrinligands 6, and corrole ligands 7. In some embodiments, the multidentateligand is a salen ligands. In other embodiments, the multidentate ligandis a porphyrin ligands. In other embodiments, the multidentate ligand isa tetraphenylporphyrin ligands. In other embodiments, the multidentateligand is a corrole ligands. Any of the foregoing ligands can beunsubstituted or can be substituted. Numerous variously substitutedanalogs of these ligands are known in the art and will be apparent tothe skilled artisan.

where each of R^(c), R^(d), R^(1a), R^(2a), R^(3a), R^(4a), R^(1a′),R^(2a′), R^(3a′), and M, is as defined and described in the classes andsubclasses herein.

In some embodiments, Lewis acids provided carbonylation catalysts usedin methods described herein comprise metal-porphinato complexes. In someembodiments, the moiety

has the structure:

wherein each of M and a is as defined above and described in the classesand subclasses herein, and

-   -   R^(d) at each occurrence is independently hydrogen, halogen,        —OR⁴, —NR^(y) ₂, —SR^(y), —CN, —NO₂, —SO₂R^(y), —SOR^(y),        —SO₂NR^(y) ₂; —CNO, —NR^(y)SO₂R^(y), —NCO, —N₃, —SiR^(y) ₃; Or        an optionally substituted group selected from the group        consisting of C₁₋₂₀ aliphatic; C₁₋₂₀ heteroaliphatic having 1-4        heteroatoms independently selected from the group consisting of        nitrogen, oxygen, and sulfur; 6- to 10-membered aryl; 5- to        10-membered heteroaryl having 1-4 heteroatoms independently        selected from nitrogen, oxygen, and sulfur; and 4- to 7-membered        heterocyclic having 1-2 heteroatoms independently selected from        the group consisting of nitrogen, oxygen, and sulfur, where two        or more R^(d) groups may be taken together to form one or more        optionally substituted rings,    -   each R^(y) is independently hydrogen, an optionally substituted        group selected the group consisting of acyl; carbamoyl,        arylalkyl; 6- to 10-membered aryl; C₁₋₁₂ aliphatic; C₁₋₁₂        heteroaliphatic having 1-2 heteroatoms independently selected        from the group consisting of nitrogen, oxygen, and sulfur; 5- to        10-membered heteroaryl having 1-4 heteroatoms independently        selected from the group consisting of nitrogen, oxygen, and        sulfur; 4- to 7-membered heterocyclic having 1-2 heteroatoms        independently selected from the group consisting of nitrogen,        oxygen, and sulfur; an oxygen protecting group; and a nitrogen        protecting group; two R^(y) on the same nitrogen atom are taken        with the nitrogen atom to form an optionally substituted 4- to        7-membered heterocyclic ring having 0-2 additional heteroatoms        independently selected from the group consisting of nitrogen,        oxygen, and sulfur; and    -   each R⁴ is independently is a hydroxyl protecting group or        R^(y).

In some embodiments, the moiety

has the structure:

wherein M, a and R^(d) are as defined above and in the classes andsubclasses herein.

In some embodiments, the moiety

has the structure:

where M, a and R^(d) are as defined above and in the classes andsubclasses herein.

In some embodiments, Lewis acids included in carbonylation catalystsused in methods described herein comprise metallo salenate complexes. Insome embodiments, the moiety

has the structure:

wherein:

-   -   M, and a are as defined above and in the classes and subclasses        herein.    -   R^(1a), R^(1a′), R^(2a), R^(2a′), R^(3a), and R^(3a′) are        independently hydrogen, halogen, —OR⁴, —NR^(y) ₂, —SR^(y), —CN,        —NO₂, —SO₂R^(y), —SOR^(y), —SO₂NR^(y) ₂; —CNO, —NR^(y)SO₂R^(y),        —NCO, —N₃, —SiR^(y) ₃; or an optionally substituted group        selected from the group consisting of C₁₋₂₀ aliphatic; C₁₋₂₀        heteroaliphatic having 1-4 heteroatoms independently selected        from the group consisting of nitrogen, oxygen, and sulfur; 6- to        10-membered aryl; 5- to 10-membered heteroaryl having 1-4        heteroatoms independently selected from nitrogen, oxygen, and        sulfur; and 4- to 7-membered heterocyclic having 1-2 heteroatoms        independently selected from the group consisting of nitrogen,        oxygen, and sulfur; wherein each R⁴, and R^(y) is independently        as defined above and described in classes and subclasses herein,    -   wherein any of (R^(2a′) and R^(3a′)), (R^(2a) and R^(3a)),        (R^(1a) and R^(2a)), and (R^(1a′) and R^(2a′)) may optionally be        taken together with the carbon atoms to which they are attached        to form one or more rings which may in turn be substituted with        one or more R^(y) groups; and    -   R^(4a) is selected from the group consisting of:

where

-   -   R^(c) at each occurrence is independently hydrogen, halogen,        —OR⁴, —NR^(y) ₂, —SR^(y), —CN, —NO₂, —SO₂R^(y), —SOR^(y),        —SO₂NR^(y) ₂; —CNO, —NR^(y)SO₂R^(y), —NCO, —N₃, —SiR^(y) ₃; or        an optionally substituted group selected from the group        consisting of C₁₋₂₀ aliphatic; C₁₋₂₀ heteroaliphatic having 1-4        heteroatoms independently selected from the group consisting of        nitrogen, oxygen, and sulfur; 6- to 10-membered aryl; 5- to        10-membered heteroaryl having 1-4 heteroatoms independently        selected from nitrogen, oxygen, and sulfur; and 4- to 7-membered        heterocyclic having 1-2 heteroatoms independently selected from        the group consisting of nitrogen, oxygen, and sulfur;        wherein:    -   two or more R^(c) groups may be taken together with the carbon        atoms to which they are attached and any intervening atoms to        form one or more rings;    -   when two R^(c) groups are attached to the same carbon atom, they        may be taken together along with the carbon atom to which they        are attached to form a moiety selected from the group consisting        of: a 3- to 8-membered spirocyclic ring, a carbonyl, an oxime, a        hydrazone, an imine; and an optionally substituted alkene;    -   wherein R⁴ and R^(y) are as defined above and in classes and        subclasses herein;    -   Y is a divalent linker selected from the group consisting of:        —NR^(y)—, —N(R^(y))C(O)—, —C(O)NR^(y)—, —O—, —C(O)—, —OC(O)—,        —C(O)O—, —S—, —SO—, —SO₂—, —C(═S)—, —C(═NR^(y))—, —N═N—; a        polyether; a C₃ to C₈ substituted or unsubstituted carbocycle;        and a C₁ to C₈ substituted or unsubstituted heterocycle;    -   m′ is 0 or an integer from 1 to 4, inclusive;    -   q is 0 or an integer from 1 to 4, inclusive; and    -   x is 0, 1, or 2.

In some embodiments, a provided Lewis acid comprises a metallo salencompound, as shown in formula Ia:

wherein each of M, R^(d), and a, is as defined above and in the classesand subclasses herein,

represents is an optionally substituted moiety linking the two nitrogenatoms of the diamine portion of the salen ligand, where

is selected from the group consisting of a C₃-C₁₄ carbocycle, a C₆-C₁₀aryl group, a C₃-C₁₄ heterocycle, and a C₅-C₁₀ heteroaryl group; or anoptionally substituted C₂₋₂₀ aliphatic group, wherein one or moremethylene units are optionally and independently replaced by —NR^(y)—,—N(R^(y))C(O)—, —C(O)N(R^(y))—, —OC(O)N(R^(y))—, —N(R^(y))C(O)O—,—OC(O)O—, —O—, —C(O)—, —OC(O)—, —C(O)O—, —S—, —SO—, —SO₂—, —C(═S)—,—C(═NR^(y))—, —C(═NOR^(y))— or —N═N—.

In some embodiments metal complexes having formula Ia above, at leastone of the phenyl rings comprising the salicylaldehyde-derived portionof the metal complex is independently selected from the group consistingof:

In some embodiments, a provided Lewis acid comprises a metallo salencompound, conforming to one of formulae Va or Vb:

where M, a, R^(d), R^(1a), R^(3a), R^(1a′), R^(3a′), and

, are as defined above and in the classes and subclasses herein.

In some embodiments of metal complexes having formulae Va or Vb, eachR^(1a) and R^(3a) is, independently, optionally substituted C₁-C₂₀aliphatic.

In some embodiments, the moiety

comprises an optionally substituted 1,2-phenyl moiety.

In some embodiments, Lewis acids included in carbonylation catalystsused in methods described herein comprise metal-tmtaa complexes. In someembodiments, the moiety

has the structure:

where M, a and R^(d) are as defined above and in the classes andsubclasses herein, and

R^(e) at each occurrence is independently hydrogen, halogen, —OR,—NR^(y) ₂, —SR, —CN, —NO₂, —SO₂R^(y), —SOR^(y), —SO₂NR^(y) ₂; —CNO,—NR^(y)SO₂R^(y), —NCO, —N₃, —SiR^(y) ₃; or an optionally substitutedgroup selected from the group consisting of C₁₋₂₀ aliphatic; C₁₋₂₀heteroaliphatic having 1-4 heteroatoms independently selected from thegroup consisting of nitrogen, oxygen, and sulfur; 6- to 10-memberedaryl; 5- to 10-membered heteroaryl having 1-4 heteroatoms independentlyselected from nitrogen, oxygen, and sulfur; and 4- to 7-memberedheterocyclic having 1-2 heteroatoms independently selected from thegroup consisting of nitrogen, oxygen, and sulfur.

In some embodiments, the moiety

has the structure:

where each of M, a, R^(c) and R^(d) is as defined above and in theclasses and subclasses herein.

In some embodiments, where carbonylation catalysts used in methodsdescribed herein include a Lewis acidic metal complex, the metal atom isselected from the periodic table groups 2-13, inclusive. In someembodiments, M is a transition metal selected from the periodic tablegroups 4, 6, 11, 12 and 13. In some embodiments, M is aluminum,chromium, titanium, indium, gallium, zinc cobalt, or copper. In someembodiments, M is aluminum. In other embodiments, M is chromium.

In some embodiments, M has an oxidation state of +2. In someembodiments, M is Zn(II), Cu(II), Mn(II), Co(II), Ru(II), Fe(II),Co(II), Rh(II), Ni(II), Pd(II) or Mg(II). In some embodiments M isZn(II). In some embodiments M is Cu(II).

In some embodiments, M has an oxidation state of +3. In someembodiments, M is Al(III), Cr(III), Fe(III), Co(III), Ti(III) In(III),Ga(III) or Mn(III). In some embodiments M is Al(III). In someembodiments M is Cr(III).

In some embodiments, M has an oxidation state of +4. In someembodiments, M is Ti(IV) or Cr(IV).

In some embodiments, M¹ and M² are each independently a metal atomselected from the periodic table groups 2-13, inclusive. In someembodiments, M is a transition metal selected from the periodic tablegroups 4, 6, 11, 12 and 13. In some embodiments, M is aluminum,chromium, titanium, indium, gallium, zinc cobalt, or copper. In someembodiments, M is aluminum. In other embodiments, M is chromium. In someembodiments, M¹ and M² are the same. In some embodiments, M¹ and M² arethe same metal, but have different oxidation states. In someembodiments, M¹ and M² are different metals.

In some embodiments, one or more of M¹ and M² has an oxidation state of+2. In some embodiments, M¹ is Zn(II), Cu(II), Mn(II), Co(II), Ru(II),Fe(II), Co(II), Rh(II), Ni(II), Pd(II) or Mg(II). In some embodiments M¹is Zn(II). In some embodiments M¹ is Cu(II). In some embodiments, M² isZn(II), Cu(II), Mn(II), Co(II), Ru(II), Fe(II), Co(II), Rh(II), Ni(II),Pd(II) or Mg(II). In some embodiments M² is Zn(II). In some embodimentsM² is Cu(II).

In some embodiments, one or more of M¹ and M² has an oxidation state of+3. In some embodiments, M¹ is Al(III), Cr(III), Fe(III), Co(III),Ti(III) In(III), Ga(III) or Mn(III). In some embodiments M¹ is Al(III).In some embodiments M¹ is Cr(III). In some embodiments, M² is Al(III),Cr(III), Fe(III), Co(III), Ti(III) In(III), Ga(III) or Mn(III). In someembodiments M² is Al(III). In some embodiments M² is Cr(III).

In some embodiments, one or more of M¹ and M² has an oxidation state of+4. In some embodiments, M¹ is Ti(IV) or Cr(IV). In some embodiments, M²is Ti(IV) or Cr(IV).

In some embodiments, the metal-centered Lewis-acidic component of thecarbonylation catalyst includes a dianionic tetradentate ligand. In someembodiments, the dianionic tetradentate ligand is selected from thegroup consisting of: porphyrin ligand; salen ligand;dibenzotetramethyltetraaza[14]annulene (tmtaa) ligand; phthalocyaninateligand; and the Trost ligand.

In some embodiments, the carbonylation catalyst includes a carbonylcobaltate in combination with an aluminum porphyrin compound. In someembodiments, the carbonylation catalyst is [(TPP)Al(THF)₂][Co(CO)₄]where TPP stands for tetraphenylporphyrin and THF stands fortetrahydrofuran.

In some embodiments, the carbonylation catalyst includes a carbonylcobaltate in combination with a chromium porphyrin compound.

In some embodiments, the carbonylation catalyst includes a carbonylcobaltate in combination with a chromium salen compound. In someembodiments, the carbonylation catalyst includes a carbonyl cobaltate incombination with a chromium salophen compound.

In some embodiments, the carbonylation catalyst includes a carbonylcobaltate in combination with an aluminum salen compound. In someembodiments, the carbonylation catalyst includes a carbonyl cobaltate incombination with an aluminum salophen compound.

In some embodiments, one or more neutral two electron donors coordinateto M M¹ or M² and fill the coordination valence of the metal atom. Insome embodiments, the neutral two electron donor is a solvent molecule.In some embodiments, the neutral two electron donor is an ether. In someembodiments, the neutral two electron donor is tetrahydrofuran, diethylether, acetonitrile, carbon disulfide, or pyridine. In some embodiments,the neutral two electron donor is tetrahydrofuran. In some embodiments,the neutral two electron donor is an epoxide. In some embodiments, theneutral two electron donor is an ester or a lactone.

BPL to PPL

In certain embodiments where the BPL conversion comprises polymerizingthe BPL, the method includes contacting the BPL with a polymerizationcatalyst, optionally in the presence of one or more solvents. Suitablesolvents can include, for example, hydrocarbons, ethers, esters,ketones, nitriles, amides, sulfones, and halogenated hydrocarbons. Incertain embodiments, the solvent is selected such that the polymerformed is soluble in the reaction medium. In certain embodiments, thesolvent is selected such that the polymer formed is insoluble, or atleast partially insoluble, in the reaction medium.

In certain embodiments where the BPL conversion comprises polymerizingthe BPL to form a PPL, the conversion comprises a continuouspolymerization. Such continuous polymerizations can be conducted in acontinuous stirred tank reactor or a plug flow reactor such that polymeror polymer solution is withdrawn at essentially the same rate it isformed. Polymerization of BPL can be performed with a number ofpolymerization initiators including for example alcohols, amines,polyols, polyamines, and diols, amongst others. Further, a variety ofcatalysts may be used in the polymerization reaction, including forexample metals (e.g., lithium, sodium, potassium, magnesium, calcium,zinc, aluminum, titanium, cobalt, etc.) metal oxides, carbonates ofalkali- and alkaline earth metals, borates, silicates, of variousmetals. In some variations, catalysts that may be used in thepolymerization reaction, include for example metals (e.g., lithium,sodium, potassium, magnesium, calcium, zinc, aluminum, titanium, cobalt,etc.) metal oxides, salts of alkali and alkaline earth metals (such ascarbonates, borates, hydroxides, alkoxides, and carboxylates), andborates, silicates, or salts of other metals.

Polymerization Catalysts

Many catalysts are known for the ring-opening polymerization of lactones(such as caprolactone and beta lactones). Any such catalyst can beemployed in the BPL polymerization processes described herein.

Catalysts suitable for the ring-opening polymerization of the methodsherein are disclosed, for example, in: Journal of the American ChemicalSociety (2002), 124(51), 15239-15248 Macromolecules, vol. 24, No. 20,pp. 5732-5733, Journal of Polymer Science, Part A-1, vol. 9, No. 10, pp.2775-2787; Inoue, S., Y. Tomoi, T. Tsuruta & J. Furukawa;Macromolecules, vol. 26, No. 20, pp. 5533-5534; Macromolecules, vol. 23,No. 13, pp. 3206-3212; Polymer Preprints (1999), 40(1), 508-509;Macromolecules, vol. 21, No. 9, pp. 2657-2668; and Journal ofOrganometallic Chemistry, vol. 341, No. 1-3, pp. 83-9; and in U.S. Pat.Nos. 3,678,069, 3,169,945, 6,133,402; 5,648,452; 6,316,590; 6,538,101;and 6,608,170.

In certain embodiments, suitable catalysts include carboxylate salts ofmetal ions or organic cations. In certain embodiments, a carboxylatesalt is other than a carbonate.

In certain embodiments, the polymerization catalyst is combined with BPLin a molar ratio up to about 1:100,000 polymerization catalyst:BPL. Incertain embodiments, the ratio is from about 1:100,000 to about 25:100polymerization catalyst:BPL. In certain embodiments, the polymerizationcatalyst is combined with BPL in a molar ratio of about 1:50,000polymerization catalyst:BPL to about 1:25,000 polymerizationcatalyst:BPL. In certain embodiments, the polymerization catalyst iscombined with BPL in a molar ratio of about 1:25,000 polymerizationcatalyst:BPL to about 1:10,000 polymerization catalyst:BPL. In certainembodiments, the polymerization catalyst is combined with BPL in a molarratio of about 1:20,000 polymerization catalyst:BPL to about 1:10,000polymerization catalyst:BPL. In certain embodiments, the polymerizationcatalyst is combined with BPL in a molar ratio of about 1:15,000polymerization catalyst:BPL to about 1:5,000 polymerizationcatalyst:BPL. In certain embodiments, the polymerization catalyst iscombined with BPL in a molar ratio of about 1:5,000 polymerizationcatalyst:BPL to about 1:1,000 polymerization catalyst:BPL. In certainembodiments, the polymerization catalyst is combined with BPL in a molarratio of about 1:2,000 polymerization catalyst:BPL to about 1:500polymerization catalyst:BPL. In certain embodiments, the polymerizationcatalyst is combined with BPL in a molar ratio of about 1:1,000polymerization catalyst:BPL to about 1:200 polymerization catalyst:BPL.In certain embodiments, the polymerization catalyst is combined with BPLin a molar ratio of about 1:500 polymerization catalyst:BPL to about1:100 polymerization catalyst:BPL. In certain embodiments the molarratio of polymerization catalyst:BPL is about 1:50,000, 1:25,000,1:15,000, 1:10,000, 1:5,000, 1:1,000, 1:500, 1:250 or a range includingany two of these values. In certain embodiments the molar ratio ofpolymerization catalyst:BPL is about 1:100, 5:100, 10:100, 15:100,20:100, 25:100 or a range including any two of these values. In certainembodiments, the polymerization catalyst is combined with BPL in a molarratio of about 1:100 polymerization catalyst:BPL to about 25:100polymerization catalyst:BPL. In certain embodiments the molar ratio ofpolymerization catalyst:BPL is about 1:100, 5:100, 10:100, 15:100,20:100, 25:100 or a range including any two of these values. In certainembodiments where the polymerization catalyst comprises a carboxylatesalt, the carboxylate has a structure such that upon initiatingpolymerization of BPL, the polymer chains produced have an acrylatechain end. In certain embodiments, the carboxylate ion on apolymerization catalyst is the anionic form of a chain transfer agent(CTA) used in the polymerization process.

In certain embodiments, the carboxylate salt of the polymerizationcatalyst is an acrylate salt (i.e., the anionic form) of a compound

or a mixture of any two or more of these, where p is from 0 to 9. Incertain embodiments, p is from 0 to 5. In certain embodiments, thecarboxylate salt of the polymerization catalyst is an acrylate salt(i.e., of compound above where p=0).

In certain embodiments, the carboxylate salt of the polymerizationcatalyst is a salt of an acrylic acid dimer:

In certain embodiments, the carboxylate salt of the polymerizationcatalyst is a salt of an acrylic acid trimer,

In certain embodiments, where the polymerization catalyst comprises acarboxylate salt, the carboxylate is the anionic form of a C₁₋₄₀carboxylic acid. In certain embodiments, the carboxylate salt can be asalt of a polycarboxylic acid (e.g. a compound having two or morecarboxylic acid groups). In certain embodiments, the carboxylatecomprises the anion of a C₁₋₂₀ carboxylic acid. In certain embodiments,the carboxylate comprises the anion of a C₁₋₁₂ carboxylic acid. Incertain embodiments, the carboxylate comprises the anion of a C₁₋₈carboxylic acid. In certain embodiments, the carboxylate comprises theanion of a C₁₋₄ carboxylic acid. In certain embodiments, the carboxylatecomprises the anion of an optionally substituted benzoic acid. Incertain embodiments, the carboxylate is selected from the groupconsisting of: formate, acetate, propionate, valerate, butyrate, C₅₋₁₀aliphatic carboxylate, and C₁₀₋₂₀ aliphatic carboxylate.

As noted, in certain embodiments, the polymerization catalyst comprisesa carboxylate salt of an organic cation. In certain embodiments, thepolymerization catalyst comprises a carboxylate salt of a cation whereinthe positive charge is located at least partially on a nitrogen, sulfur,or phosphorus atom. In certain embodiments, the polymerization catalystcomprises a carboxylate salt of a nitrogen cation. In certainembodiments, the polymerization catalyst comprises a carboxylate salt ofa cation selected from the group consisting of: ammonium, amidinium,guanidinium, a cationic form of a nitrogen heterocycle, and anycombination of two or more of these. In certain embodiments, thepolymerization catalyst comprises a carboxylate salt of a phosphoruscation. In certain embodiments, the polymerization catalyst comprises acarboxylate salt of a cation selected from the group consisting of:phosphonium and phosphazenium. In certain embodiments, thepolymerization catalyst comprises a carboxylate salt of asulfur-containing cation. In certain embodiments, the polymerizationcatalyst comprises a sulfonium salt.

In certain embodiments, the polymerization catalyst comprises acarboxylate salt of a metal. In certain embodiments, the polymerizationcatalyst comprises a carboxylate salt of a alkali or alkaline earthmetal. In certain embodiments, the polymerization catalyst comprises acarboxylate salt of an alkali metal. In certain embodiments, thepolymerization catalyst comprises a carboxylate salt of sodium orpotassium. In certain embodiments, the polymerization catalyst comprisesa carboxylate salt of sodium.

In certain embodiments, the polymerization catalyst comprises acarboxylate salt of a protonated amine:

where:

each R¹ and R² is independently hydrogen or an optionally substitutedradical selected from the group consisting of C₁₋₂₀ aliphatic; C₁₋₂₀heteroaliphatic; a 3- to 8-membered saturated or partially unsaturatedmonocyclic carbocycle; a 7- to 14-membered saturated or partiallyunsaturated polycyclic carbocycle; a 5- to 6-membered monocyclicheteroaryl ring having 1-4 heteroatoms independently selected fromnitrogen, oxygen, or sulfur; an 8- to 14-membered polycyclic heteroarylring having 1-5 heteroatoms independently selected from nitrogen,oxygen, or sulfur; a 3- to 8-membered saturated or partially unsaturatedmonocyclic heterocyclic ring having 1-3 heteroatoms independentlyselected from nitrogen, oxygen, or sulfur; a 6- to 14-membered saturatedor partially unsaturated polycyclic heterocycle having 1-5 heteroatomsindependently selected from nitrogen, oxygen, or sulfur; phenyl; or an8- to 14-membered polycyclic aryl ring; wherein R¹ and R² can be takentogether with intervening atoms to form one or more optionallysubstituted rings optionally containing one or more additionalheteroatoms; and

each R³ is independently hydrogen or an optionally substituted radicalselected from the group consisting of C₁₋₂₀ aliphatic; C₁₋₂₀heteroaliphatic; a 3- to 8-membered saturated or partially unsaturatedmonocyclic carbocycle; a 7- to 14-membered saturated or partiallyunsaturated polycyclic carbocycle; a 5- to 6-membered monocyclicheteroaryl ring having 1-4 heteroatoms independently selected fromnitrogen, oxygen, or sulfur; an 8- to 14-membered polycyclic heteroarylring having 1-5 heteroatoms independently selected from nitrogen,oxygen, or sulfur; a 3- to 8-membered saturated or partially unsaturatedmonocyclic heterocyclic ring having 1-3 heteroatoms independentlyselected from nitrogen, oxygen, or sulfur; a 6- to 14-membered saturatedor partially unsaturated polycyclic heterocycle having 1-5 heteroatomsindependently selected from nitrogen, oxygen, or sulfur; phenyl; or an8- to 14-membered polycyclic aryl ring; wherein an R³ group can be takenwith an R¹ or R² group to form one or more optionally substituted rings.

In certain embodiments where the polymerization catalyst comprises acarboxylate salt of a protonated amine, the protonated amine is selectedfrom the group consisting of:

In certain embodiments, the polymerization catalyst comprises acarboxylate salt of a quaternary ammonium salt:

where:

-   -   each R¹, R² and R³ is described above; and    -   each R⁴ is independently hydrogen or an optionally substituted        radical selected from the group consisting of C₁₋₂₀ aliphatic;        C₁₋₂₀ heteroaliphatic; a 3- to 8-membered saturated or partially        unsaturated monocyclic carbocycle; a 7- to 14-membered saturated        or partially unsaturated polycyclic carbocycle; a 5- to        6-membered monocyclic heteroaryl ring having 1-4 heteroatoms        independently selected from nitrogen, oxygen, or sulfur; an 8-        to 14-membered polycyclic heteroaryl ring having 1-5 heteroatoms        independently selected from nitrogen, oxygen, or sulfur; a 3- to        8-membered saturated or partially unsaturated monocyclic        heterocyclic ring having 1-3 heteroatoms independently selected        from nitrogen, oxygen, or sulfur; a 6- to 14-membered saturated        or partially unsaturated polycyclic heterocycle having 1-5        heteroatoms independently selected from nitrogen, oxygen, or        sulfur; phenyl; or an 8- to 14-membered polycyclic aryl ring;        wherein an R⁴ group can be taken with an R¹, R² or R³ group to        form one or more optionally substituted rings.

In certain embodiments, a polymerization catalyst comprises acarboxylate salt of a guanidinium group:

wherein each R¹ and R² is independently as defined above and describedin classes and subclasses herein. In certain embodiments, each R¹ and R²is independently hydrogen or C₁₋₂₀ aliphatic. In certain embodiments,each R¹ and R² is independently hydrogen or C₁₋₁₂ aliphatic. In certainembodiments, each R¹ and R² is independently hydrogen or C₁₋₂₀heteroaliphatic. In certain embodiments, each R¹ and R² is independentlyhydrogen or phenyl. In certain embodiments, each R¹ and R² isindependently hydrogen or 8- to 10-membered aryl. In certainembodiments, each R¹ and R² is independently hydrogen or 5- to10-membered heteroaryl. In certain embodiments, each R¹ and R² isindependently hydrogen or 3- to 7-membered heterocyclic. In certainembodiments, one or more of R¹ and R² is optionally substituted C₁₋₂aliphatic.

In certain embodiments, any two or more R¹ or R² groups are takentogether with intervening atoms to form one or more optionallysubstituted carbocyclic, heterocyclic, aryl, or heteroaryl rings. Incertain embodiments, R¹ and R² groups are taken together to form anoptionally substituted 5- or 6-membered ring. In certain embodiments,three or more R¹ and/or R² groups are taken together to form anoptionally substituted fused ring system.

In certain embodiments, an R¹ and R² group are taken together withintervening atoms to form a compound selected from:

wherein each R¹ and R² is independently as defined above and describedin classes and subclasses herein, and Ring G is an optionallysubstituted 5- to 7-membered saturated or partially unsaturatedheterocyclic ring.

It will be appreciated that when a guanidinium cation is depicted as

all such resonance forms are contemplated and encompassed by the presentdisclosure. For example, such groups can also be depicted as

In specific embodiments, a guanidinium cation is selected from the groupconsisting of:

In certain embodiments, a polymerization catalyst comprises acarboxylate salt of a sulfonium group or an arsonium group, such as

wherein each of R¹, R², and R³ are as defined above and described inclasses and subclasses herein.

In specific embodiments, an arsonium cation is selected from the groupconsisting of:

In certain embodiments, a polymerization catalyst comprises acarboxylate salt of an optionally substituted nitrogen-containingheterocycle. In certain embodiments, the nitrogen-containing heterocycleis an aromatic heterocycle. In certain embodiments, the optionallysubstituted nitrogen-containing heterocycle is selected from the groupconsisting of: pyridine, imidazole, pyrrolidine, pyrazole, quinoline,thiazole, dithiazole, oxazole, triazole, pyrazolem, isoxazole,isothiazole, tetrazole, pyrazine, thiazine, and triazine.

In certain embodiments, a nitrogen-containing heterocycle includes aquaternarized nitrogen atom. In certain embodiments, anitrogen-containing heterocycle includes an iminium moiety such as

In certain embodiments, the optionally substituted nitrogen-containingheterocycle is selected from the group consisting of pyridinium,imidazolium, pyrrolidinium, pyrazolium, quinolinium, thiazolium,dithiazolium, oxazolium, triazolium, isoxazolium, isothiazolium,tetrazolium, pyrazinium, thiazinium, and triazinium.

In certain embodiments, a nitrogen-containing heterocycle is linked to ametal complex via a ring nitrogen atom. In certain embodiments, a ringnitrogen to which the attachment is made is thereby quaternized, and Incertain embodiments, linkage to a metal complex takes the place of anN—H bond and the nitrogen atom thereby remains neutral. In certainembodiments, an optionally substituted N-linked nitrogen-containingheterocycle is a pyridinium derivative. In certain embodiments,optionally substituted N-linked nitrogen-containing heterocycle is animidazolium derivative. In certain embodiments, optionally substitutedN-linked nitrogen-containing heterocycle is a thiazolium derivative. Incertain embodiments, optionally substituted N-linked nitrogen-containingheterocycle is a pyridinium derivative.

In certain embodiments, a polymerization catalyst comprises acarboxylate salt of

In certain embodiments, ring A is an optionally substituted, 5- to10-membered heteroaryl group. In certain embodiments, Ring A is anoptionally substituted, 6-membered heteroaryl group. In certainembodiments, Ring A is a ring of a fused heterocycle. In certainembodiments, Ring A is an optionally substituted pyridyl group.

In specific embodiments, a nitrogen-containing heterocyclic cation isselected from the group consisting of:

In certain embodiments, a polymerization catalyst comprises acarboxylate salt of

where each R¹, R², and R³ is independently as defined above anddescribed in classes and subclasses herein.

In certain embodiments, a polymerization catalyst comprises acarboxylate salt of

wherein each R¹ and R² is independently as defined above and describedin classes and subclasses herein.

In certain embodiments, a polymerization catalyst comprises acarboxylate salt of

wherein each R¹, R², and R³ is independently as defined above anddescribed in classes and subclasses herein.

In certain embodiments, a polymerization catalyst comprises acarboxylate salt of

wherein each of R¹, R², R⁶, and R⁷ is as defined above and described inclasses and subclasses herein.

In certain embodiments, R⁶ and R⁷ are each independently an optionallysubstituted group selected from the group consisting of C₁₋₂₀ aliphatic;C₁₋₂₀ heteroaliphatic; phenyl, and 8-10-membered aryl. In certainembodiments, R⁶ and R⁷ are each independently an optionally substitutedC₁₋₂₀ aliphatic. In certain embodiments, R⁶ and R⁷ are eachindependently an optionally substituted C₁₋₂₀ heteroaliphatic having. Incertain embodiments, R⁶ and R⁷ are each independently an optionallysubstituted phenyl or 8-10-membered aryl. In certain embodiments, R⁶ andR⁷ are each independently an optionally substituted 5- to 10-memberedheteroaryl. In certain embodiments, R⁶ and R⁷ can be taken together withintervening atoms to form one or more rings selected from the groupconsisting of: optionally substituted C₃-C₁₄ carbocycle, optionallysubstituted C₃-C₁₄ heterocycle, optionally substituted C₆-C₁₀ aryl, andoptionally substituted 5- to 10-membered heteroaryl. In certainembodiments, R⁶ and R⁷ are each independently an optionally substitutedC₁₋₆ aliphatic. In certain embodiments, each occurrence of R⁶ and R⁷ isindependently methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl,octyl, or benzyl. In certain embodiments, each occurrence of R⁶ and R⁷is independently perfluoro. In certain embodiments, each occurrence ofR⁶ and R⁷ is independently —CF₂CF₃.

In certain embodiments, a polymerization catalyst comprises acarboxylate salt of

wherein each R¹ and R² is independently as defined above and describedin classes and subclasses herein.

In certain embodiments, a polymerization catalyst comprises acarboxylate salt of

wherein each R¹, R², and R³ is independently as defined above anddescribed in classes and subclasses herein.

In certain embodiments, a cation is

wherein each R¹ and R² is independently as defined above and describedin classes and subclasses herein.

In certain embodiments, a polymerization catalyst comprises acarboxylate salt of

wherein each R¹ and R² is independently as defined above and describedin classes and subclasses herein.

In certain embodiments, a polymerization catalyst comprises acarboxylate salt of

wherein each R¹, R², and R³ is independently as defined above anddescribed in classes and subclasses herein.

In certain embodiments, a polymerization catalyst comprises acarboxylate salt of

wherein each R¹ and R² is independently as defined above and describedin classes and subclasses herein. In certain embodiments, suitablecatalysts include transition metal compounds. In certain embodiments,suitable catalysts include acid catalysts. In certain embodiments, thecatalyst is a heterogeneous catalyst.

In certain embodiments, the carboxylate salt of the polymerizationcatalyst is a compound:

where p is from 0 to 9 and R^(a) is a non-volatile moiety. The term“non-volatile moiety,” as used herein, refers to a moiety or material towhich a carboxylate can be attached, and that renders the carboxylate(e.g., when p=0) non-volatile to pyrolysis conditions. In certainembodiments, a non-volatile moiety is selected from the group consistingof glass surfaces, silica surfaces, plastic surfaces, metal surfacesincluding zeolites, surfaces containing a metallic or chemical coating,membranes (e.g., nylon, polysulfone, silica), micro-beads (e.g., latex,polystyrene, or other polymer), and porous polymer matrices (e.g.,polyacrylamide, polysaccharide, polymethacrylate). In certainembodiments, a non-volatile moiety has a molecular weight above 100,200, 500, or 1000 g/mol. In certain embodiments, a non-volatile moietyis part of a fixed or packed bed system. In certain embodiments, anon-volatile moiety is part of a fixed or packed bed system comprisingpellets (e.g., zeolite).

In certain embodiments, p is from 0 to 5. In certain embodiments, thecarboxylate salt of the polymerization catalyst is an acrylate salt(i.e., of the above compound where p=0).

In certain embodiments, a suitable carboxylate catalyst isheterogeneous. In certain embodiments, a suitable carboxylate catalystwill remain in a reaction zone as a salt or melt after removal of allother products, intermediates, starting materials, byproducts, and otherreaction components. In certain embodiments, a suitable carboxylatecatalyst (i.e., the above compound where p is from 0 to 9) will remainin a reaction zone as a salt or melt after removal of all AA productstream.

In certain embodiments, a catalyst is recycled for further use in areaction zone. In certain embodiments, a salt or melt catalyst isrecycled to a reaction zone. In certain embodiments, provided methodsfurther comprise withdrawing a recycling stream of homogeneous catalystto a reaction zone. In certain embodiments, such a recycling streamcomprises a high boiling solvent, wherein the solvent's boiling point isabove the pyrolysis temperature of PPL and the catalyst remains in thehigh boiling solvent during pyrolysis while the withdrawn product streamis gaseous.

In some variations of the foregoing, the catalyst recycling stream hasless than 0.01 wt % of oxygen. In certain variations, the catalystrecycling stream has less than 0.005 wt % oxygen. In certain variations,the catalyst recycling stream has less than 200 ppm oxygen. In certainvariations, the catalyst recycling stream has less than 150 ppm oxygen,less than 100 ppm oxygen, less than 50 ppm oxygen, less than 20 ppmoxygen, less than 10 ppm oxygen, less than 5 ppm oxygen, less than 2 ppmoxygen, or less than 1 ppm oxygen. In certain variations, the catalystrecycling stream has less than 0.05 wt % water. In certain variations,the catalyst recycling stream has less than 0.01 wt % water. In certainvariations, the catalyst recycling stream has less than 1000 ppm water.In certain variations, the catalyst recycling stream has less than 500ppm water, less than 400 ppm water, less than 250 ppm water, less than200 ppm water, less than 150 ppm water, less than 100 ppm water, lessthan 50 ppm water, or less than 10 ppm water. In certain variations, thecatalyst recycling stream has less than 200 ppm of oxygen and watercombined.

PPL to AA

In some embodiments, BPL is converted to AA (e.g., GAA) withoutisolation of the intermediate PPL, wherein the PPL formed bypolymerization of BPL is concurrently converted to AA (e.g., GAA) viapyrolysis in the same reaction zone (e.g., a “one-pot” method). Incertain embodiments, the reaction zone containing the reaction of BPL toPPL is maintained at a temperature at or above the pyrolysis temperatureof PPL such that the thermal decomposition of PPL produces AA. Withoutwishing to be bound by any particular theory, it is believed that insuch embodiments as BPL reacts with AA to start polymer chains, thermaldecomposition will degrade the polymer to AA.

A one-pot BPL conversion to AA can be operated within a variety oftemperature and pressure ranges. In certain embodiments, the temperaturecan range from about 150° C. to about 300° C. In certain embodiments,the temperature ranges from about 150° C. to about 200° C. In certainembodiments, the temperature ranges from about 150° C. to about 250° C.In certain embodiments, the temperature ranges from about 175° C. toabout 300° C. n some embodiments, the temperature ranges from about 200°C. to about 250° C. In certain embodiments, the temperature ranges fromabout 225° C. to about 275° C. In certain embodiments, the temperatureranges from about 250° C. to about 300° C. In certain embodiments, thetemperature ranges from about 200° C. to about 300° C.

In certain embodiments, the pressure used in provided methods andsystems can range from about 0.01 atmospheres to about 500 atmospheres(absolute). In certain embodiments, the pressure can range from about0.01 atmospheres to about 10 atmospheres (absolute). In certainembodiments, the pressure can range from about 0.01 atmospheres to about50 atmospheres (absolute). In certain embodiments, the pressure canrange from about 1 atmosphere to about 10 atmospheres (absolute). Incertain embodiments, the pressure can range from about 1 atmosphere toabout 50 atmospheres (absolute). In certain embodiments, the pressurecan range from about 1 atmosphere to about 100 atmospheres (absolute).In certain embodiments, the pressure can range from about 10 atmospheresto about 50 atmospheres (absolute). In certain embodiments, the pressurecan range from about 10 atmospheres to about 100 atmospheres (absolute).In certain embodiments, the pressure can range from about 50 atmospheresto about 100 atmospheres (absolute). In certain embodiments, thepressure can range from about 50 atmospheres to about 200 atmospheres(absolute). In certain embodiments, the pressure can range from about100 atmospheres to about 200 atmospheres (absolute). In certainembodiments, the pressure can range from about 100 atmospheres to about250 atmospheres (absolute). In certain embodiments, the pressure canrange from about 200 atmospheres to about 300 atmospheres (absolute). Incertain embodiments, the pressure can range from about 200 atmospheresto about 500 atmospheres (absolute). In certain embodiments, thepressure can range from about 250 atmospheres to about 500 atmospheres(absolute).

In some embodiments, the pressure used in provided methods and systemsfor converting PPL to AA is less than about 5 atmospheres (absolute). Insome embodiments, the pressure used in provided methods and systems isless than about 1 atmosphere (absolute). In some embodiments, thepressure can range from about 0.01 atmospheres to about 1 atmosphere(absolute). In some embodiments, the pressure can range from about 0.1atmospheres to about 0.8 atmospheres (absolute). In some embodiments,the pressure can range from about 0.1 atmospheres to about 0.5atmospheres (absolute). In some embodiments, the pressure can range fromabout 0.01 atmospheres to about 0.1 atmospheres (absolute). In someembodiments, the pressure can range from about 0.4 atmospheres to about1 atmosphere (absolute). In some embodiments, the pressure can rangefrom about 0.05 atmospheres to about 0.1 atmospheres (absolute).

The conversion of PPL to AA can be operated within a variety oftemperature and pressure ranges. In certain embodiments, the temperaturecan range from about 150° C. to about 300° C. In certain embodiments,the temperature ranges from about 150° C. to about 200° C. In certainembodiments, the temperature ranges from about 150° C. to about 250° C.In certain embodiments, the temperature ranges from about 175° C. toabout 300° C. n some embodiments, the temperature ranges from about 200°C. to about 250° C. In certain embodiments, the temperature ranges fromabout 225° C. to about 275° C. In certain embodiments, the temperatureranges from about 250° C. to about 300° C. In certain embodiments, thetemperature ranges from about 200° C. to about 300° C.

The conversion of PPL to AA can be performed in a variety of apparatus.In certain embodiments, the conversion of PPL to AA is performed in acontinuous reactor. In certain embodiments, the continuous reactor isselected from a continuous stirred tank reactor, a plug flow reactor,and a combination of two or more of these. In certain embodiments, thecontinuous reactor is selected from the group consisting of a wiped filmevaporator, a falling film evaporator, a loop reactor, a fluidized bedreactor, a circulating fluidized bed reactor a devolatilizing extruder,a vented tubular reactor and a heavy oil reactor. In certainembodiments, the conversion of PPL to AA comprises a wiped filmevaporator. In certain embodiments, the conversion of PPL to AAcomprises a falling film evaporator. In certain embodiments, theconversion of PPL to AA comprises a fluidized bed reactor. In certainembodiments, the conversion of PPL to AA comprises a devolatilizlingextruder. In certain embodiments, the conversion of PPL to AA comprisesa circulating fluidized bed reactor.

AA to PAA & SAPs

Monomeric AA (including GAA) precursors of SAPs must react to completionor nearly so to prevent or minimize the presence of residual unreactedmonomer in the SAP or products, such as diapers, made from the SAP. Insome embodiments, AA and PAA, or a salt thereof, made from the disclosedsystems and methods are substantially free from compounds that derivesfrom the oxidation of propylene and/or aldehyde impurities. As such, thedisclosed AA reacts more fully to produce PAA, sodium polyacrylate andother co-polymers, having minimal or substantially no residual unreactedAA, suitable for incorporated into SAPs.

As used herein, the term “superabsorbent polymer” (SAP) refers to awater-swellable, water-insoluble polymer capable, under the mostfavorable conditions, of absorbing at least about 10 times its weight inan aqueous solution containing 0.9 weight percent sodium chloride. ASAP's ability to absorb water may depend on the ionic concentration ofthe aqueous solution. In deionized and distilled water, a SAP may absorb500 times its weight (from 30 to 60 times its own volume) and can becomeup to 99.9% liquid, but when put into a 0.9% saline solution, theabsorbency may drop to 50 times its weight.

SAPs are generally made from the polymerization of AA blended withsodium hydroxide in the presence of a radical initiator (e.g.,azobisisobutyronitrile, AIBN) to form a PAA sodium salt (sometimesreferred to as sodium polyacrylate). This polymer is presently among themost common types of SAPs. Other materials are also used to make a SAP,such as polyacrylamide copolymer, ethylene maleic anhydride copolymer,cross-linked carboxymethylcellulose, polyvinyl alcohol copolymers,cross-linked polyethylene oxide, and starch grafted copolymer ofpolyacrylonitrile, among others. SAPs are generally made using one ofthree methods: gel polymerization, suspension polymerization or solutionpolymerization.

Gel Polymerization: A mixture of frozen acrylic acid, water,cross-linking agents and UV initiator chemicals are blended and placedeither on a moving belt or in large tubs. The liquid mixture then goesinto a “reactor” which may be a long chamber with a series of strong UVlights. The UV radiation drives the polymerization and cross-linkingreactions. The resulting “logs” may be sticky gels containing 60-70%water. The logs are shredded or ground and placed in various sorts ofdriers. Additional cross-linking agent may be sprayed on the particles'surface; this “surface cross-linking” increases the product's ability toswell under pressure—a property measured as Absorbency Under Load (AUL)or Absorbency Against Pressure (AAP). The dried polymer particles arethen screened for proper particle size distribution and packaging. Thegel polymerization (GP) method is widely used for making the sodiumpolyacrylate superabsorbent polymers now used in baby diapers and otherdisposable hygienic articles.

Solution Polymerization: Solution polymers offer the absorbency of agranular polymer supplied in solution form. Solutions can be dilutedwith water prior to application, and can coat most substrates or used tosaturate them. After drying at a specific temperature for a specifictime, the result is a coated substrate with superabsorbency. Forexample, this chemistry can be applied directly onto wires and cables,though it is especially optimized for use on components such as rolledgoods or sheeted substrates.

Solution-based polymerization is commonly used today for SAP manufactureof co-polymers, particularly those with the toxic acrylamide monomer.This process is efficient and generally has a lower capital cost base.The solution process uses a water-based monomer solution to produce amass of reactant polymerized gel. The polymerization's own exothermicreaction energy is used to drive much of the process, helping reducemanufacturing cost. The reactant polymer gel is then chopped, dried andground to its final granule size. Treatments to enhance performancecharacteristics of the SAP are often accomplished after the finalgranule size is created.

Suspension Polymerization: generally requires a higher degree ofproduction control and product engineering during the polymerizationstep. This process suspends the water-based reactant in ahydrocarbon-based solvent. The net result is that the suspensionpolymerization creates the primary polymer particle in the reactorrather than mechanically in post-reaction stages. Performanceenhancements can also be made during, or just after, the reaction stage.

In selected embodiments, SAPs prepared from PAA, sodium polyacrylate,and AA that derive from the systems and methods described herein, haveless than about 1000, 500, 200, 100, 50 or 10 parts per million residualmonoethylenically unsaturated monomer, which for example may derive froman unsaturated AA monomer.

Large Scale AA Production

In another aspect, a system is provided for the production of AA, e.g.,an AA production plant, wherein the system produces AA at a rate ofabout 200 to about 1,000 kilotons per annum (kta). Presently in the art,because of limits on the equipment required to control heat and removeimpurities in the propylene oxidation process, modern acrylic acidplants generate approximately 160 kta AA from propylene-based feedstock.Without being bound by theory, the disclosed systems are capable ofproducing greater output of AA from ethylene-based feedstock. In certainembodiments, the system produces the acrylic acid (AA) from ethylene. Incertain embodiments, the AA is crude AA. In certain embodiments, the AAis glacial AA. In some embodiments, the AA is substantially free of aproduct or by product of propylene oxidation. In some embodiments, theAA is substantially free of an aldehyde impurity. In some embodiments,the AA is substantially free of furfural. In some embodiments, the AA issubstantially free of acetic acid. In some embodiments, the AA issubstantially free of stabilizers. In some embodiments, the AA issubstantially free of radical polymerization inhibitors. In someembodiments, the AA is substantially free of anti-foam agents.

Specifically, the disclosed systems include a reactor for the oxidationof ethylene to EO, a reactor for carbonylating EO with CO to produceBPL, and reactors for converting BPL to AA, optionally via PPL.

In certain embodiments, the system produces AA at a rate of about 200,250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900,950, 1,000 kta, or within a range including any two of these values.

In another aspect, a method is provided for the production of acrylicacid (AA) from ethylene in a single integrated system, the methodcomprising:

providing ethylene to an oxidative reactor that converts at least someof the ethylene to ethylene oxide (EO),

providing EO to a central reactor that converts at least some of the EOto beta propiolactone (BPL),

and at least one of the following steps:

providing BPL to a first reactor that converts at least some of the BPLto AA, and

providing BPL to a reactor that converts at least some of the BPL topolypropiolactone (PPL), and

isolating acrylic acid at a rate of about 200 to about 800 kilotons perannum (kta).

In some variations, provided is a method for producing acrylic acid (AA)from ethylene in a single integrated system, the method comprising:

providing ethylene to an oxidative reactor that converts at least someof the ethylene to ethylene oxide (EO),

providing EO to a central reactor that converts at least some of the EOto beta propiolactone (BPL),

at least the following (i) or (ii), or both (i) and (ii):

(i) providing BPL to a first reactor that converts at least some of theBPL to AA, or

(ii) providing BPL to a reactor that converts at least some of the BPLto polypropiolactone (PPL) which is optionally fed to a reactor thatconverts PPL to AA; and

(d) producing acrylic acid at a rate of about 200 to about 800 kilotonsper annum (kta).

The term “integrated system” as used herein means a single system suchas a chemical plant, confined to a single geographic location, andcomprising an abutting series of reactors or system components.

Enumerated Embodiments

The following enumerated embodiments are representative of some aspectsof the invention.

-   1. A system for the production of polyacrylic acid (PAA) from    ethylene, comprising: an oxidative reactor, comprising an inlet fed    by ethylene, an oxidative reaction zone that converts at least some    of the ethylene to ethylene oxide (EO), and an outlet which provides    an outlet stream comprising the EO,    -   a central reactor, comprising an inlet fed by an EO source, and        a carbon monoxide (CO) source, a central reaction zone that        converts at least some of the EO to beta propiolactone (BPL) or        polypropiolactone (PPL), and an outlet which provides an outlet        stream comprising the BPL or PPL,    -   one or more of (i), (ii) and (iii):        -   (i) a first reactor, comprising an inlet fed by the outlet            stream comprising BPL of the central reactor, a first            reaction zone that converts at least some of the BPL to AA,            and an outlet which provides an outlet stream comprising the            AA,        -   (ii) a second (a) reactor, comprising an inlet fed by the            outlet stream comprising BPL of the central reactor, a            second (a) reaction zone that converts at least some of the            BPL to PPL, and an outlet which provides an outlet stream            comprising the PPL, and a second (b) reactor, comprising an            inlet fed by the outlet stream comprising PPL of the            second (a) reactor, a second (b) reaction zone that converts            at least some of the PPL to AA, and an outlet which provides            an outlet stream comprising the AA, and        -   (iii) a third reactor, comprising an inlet fed by the outlet            stream comprising PPL of the central reactor, a third            reaction zone that converts at least some of the PPL to a            third product, and an outlet which provides an outlet stream            comprising the AA, and    -   (iv) a fourth reactor, comprising an inlet fed by the outlet        stream comprising AA of one or more of the first, second (b) and        third reactor, a fourth reaction zone that converts at least        some of the AA to polyacrylic acid (PAA), or a salt thereof, and        an outlet which provides an outlet stream comprising the PAA, or        a salt thereof, and    -   a controller for independently modulating production of the EO,        BPL, PPL, AA and PAA.-   2. The system of embodiment 1, comprising two of (i), (ii) and    (iii).-   3. The system of embodiment 1, comprising three of (i), (ii) and    (iii).-   4. The system of embodiment 1, wherein the system produces AA at    about 200 to about 800 kilotons per annum (kta).-   5. The system of embodiment 1, wherein the AA is glacial acrylic    acid (GAA).-   6. The system of embodiment 5, wherein the GAA is substantially free    of an aldehyde impurity or a compound that derives from the    oxidation of propylene.-   7. The system of embodiment 1, wherein the inlet to the fourth    reactor is fed by one or more reactant streams comprising sodium    hydroxide in the presence of a radical initiator to form a PAA    sodium salt.-   8. The system of embodiment 1, wherein at least some of the AA is    converted to the PAA, or a salt thereof, via gel polymerization,    suspension polymerization or solution polymerization.-   9. The system of embodiment 1, wherein the PAA, or a salt thereof,    is substantially free of an aldehyde impurity or a compound that    derives from the oxidation of propylene.-   10. The system of embodiment 1, wherein the inlet to the fourth    reactor is further fed by one or more reactant streams each    comprising a monomer to co-polymerize with GAA to form one or more    co-polymers of PAA selected from a polyacrylamide copolymer,    ethylene maleic anhydride copolymer, cross-linked    carboxymethylcellulose copolymer, polyvinyl alcohol copolymer,    cross-linked polyethylene oxide copolymer, and starch grafted    polyacrylonitrile copolymer of PAA.-   11. The system of embodiment 1, further comprising:    -   (v) a fifth reactor, comprising an inlet fed by the outlet        stream comprising PAA, or a salt thereof, of the fourth reactor,        a fifth reaction zone that converts at least some of the PAA, or        a salt thereof, to superabsorbent polymer (SAP) and an outlet        which provides an outlet stream comprising the SAP.-   12. The system of embodiment 11, wherein the inlet to the fifth    reactor is further fed by one or more reactant streams each    comprising a cross-linking agent may be sprayed on the PAA, or a    salt thereof.-   13. The system of embodiment 11, wherein the SAP comprises less than    about 1000 parts per million residual monoethylenically unsaturated    monomer, and is substantially free of an aldehyde impurity or a    compound that derives from the oxidation of propylene.-   14. An article comprising the SAP of embodiment 11.-   15. The article of embodiment 14, wherein the article is a    disposable diaper.-   16. A method, wherein the method is for the conversion of ethylene    to acrylic acid (AA) within an integrated system, the method    comprising the steps of:    -   providing an inlet stream comprising ethylene to an oxidative        reactor of the integrated system to effect conversion of at        least a portion of the provided ethylene to EO,    -   providing an inlet stream comprising EO, from the oxidative        reactor, and carbon monoxide (CO) to a central reactor of the        integrated system,    -   contacting the inlet stream with a metal carbonyl in a central        reaction zone to effect conversion of at least a portion of the        provided EO to a beta propiolactone (BPL), directing an outlet        stream comprising BPL from the central reaction zone to at least        one of:        -   (i) a first reactor, comprising an inlet fed by the outlet            stream comprising BPL of the central reactor, a first            reaction zone that converts at least some of the BPL to AA,            and an outlet from which an outlet stream comprising the AA            is obtainable,        -   (ii) a second (a) reactor, comprising an inlet fed by the            outlet stream comprising BPL of the central reactor, a            second (a) reaction zone that converts at least some of the            BPL to PPL, and an outlet from which an outlet stream            comprising the PPL is obtainable, and a second (b) reactor,            comprising an inlet fed by the outlet stream comprising PPL            of the second (a) reactor, a second (b) reaction zone that            converts at least some of the PPL to AA, and an outlet from            which an outlet stream comprising the AA is obtainable,        -   (iii) a third reactor, comprising an inlet fed by the outlet            stream comprising PPL of the central reactor, a third            reaction zone that converts at least some of the PPL to a            third product, and an outlet from which an outlet stream            comprising the AA is obtainable, and    -   obtaining AA; and    -   providing an outlet stream comprising GAA from one or more of        the first, second (b) and third reactor, to the inlet of (iv) a        fourth reactor in which at least some of the GAA is converted to        polyacrylic acid (PAA), or a salt thereof.-   17. The method of embodiment 16, wherein the AA is glacial acrylic    acid (GAA).-   18. The method of embodiment 17, wherein the GAA is substantially    free of an aldehyde impurity or a compound that derives from the    oxidation of propylene.-   19. The method of embodiment 16, wherein the PAA is substantially    free of an aldehyde impurity or a compound that derives from the    oxidation of propylene.-   20. The method of embodiment 16, further comprising:    -   providing an outlet stream comprising PAA, or a salt thereof,        from the fourth reactor, to the inlet of (v) a fifth reactor in        which at least some of the PAA, or a salt thereof, is converted        to superabsorbent polymer (SAP).-   21. The method of embodiment 20, wherein the SAP comprises less than    about 1000 parts per million residual monoethylenically unsaturated    monomer.-   22. The method of embodiment 16, wherein the GAA is converted to PAA    less than one week after the ethylene is converted to EO.-   23. The method of embodiment 16, wherein the GAA is converted to PAA    less than two days after the ethylene is converted to EO.-   24. A system for producing polyacrylic acid (PAA) from ethylene,    comprising:    -   an oxidative reactor, comprising:        -   an inlet configured to receive ethylene,        -   an oxidative reaction zone configured to convert at least            some of the ethylene to ethylene oxide (EO), and        -   an outlet configured to provide an EO stream comprising the            EO;    -   a central reactor, comprising:        -   an inlet configured to receive EO from the EO stream of the            oxidative reactor, and carbon monoxide (CO) from a CO            source,        -   a central reaction zone configured to convert at least some            of the EO to beta propiolactone (BPL) or polypropiolactone            (PPL), or a combination thereof, and        -   an outlet configured to provide a carbonylation stream            comprising the BPL, or a carbonylation stream comprising the            PPL, or a combination thereof;    -   one or more of (i), (ii) and (iii):        -   (i) a first reactor, comprising:            -   an inlet configured to receive BPL from the                carbonylation stream of the central reactor,            -   a first reaction zone configured to convert at least                some of the BPL to AA, and            -   an outlet configured to provide an AA stream comprising                the AA,        -   (ii) a second (a) reactor, comprising:            -   an inlet configured to receive BPL from the                carbonylation stream of the central reactor,            -   a second (a) reaction zone configured to convert at                least some of the BPL to PPL, and            -   an outlet configured to provide a PPL stream comprising                the PPL, and        -   a second (b) reactor, comprising:            -   an inlet configured to receive the PPL stream of the                second (a) reactor,            -   a second (b) reaction zone configured to convert at                least some of the PPL to AA, and            -   an outlet configured to provide an AA stream comprising                the AA, and        -   (iii) a third reactor, comprising:            -   an inlet configured to receive PPL from carbonylation                stream of the central reactor,            -   a third reaction zone configured to convert at least                some of the PPL to AA, and            -   an outlet configured to provide an AA stream comprising                the AA;    -   a fourth reactor, comprising:        -   an inlet configured to receive the AA stream of one or more            of the first, second (b) and third reactor,        -   a fourth reaction zone configured to convert at least some            of the AA to polyacrylic acid (PAA), or a salt thereof, and        -   an outlet configured to provide a PAA stream comprising the            PAA, or a salt thereof; and    -   a controller to independently modulate production of the EO,        BPL, PPL, AA and PAA.-   25. The system of embodiment 24, comprising two of (i), (ii) and    (iii).-   26. The system of embodiment 24, comprising three of (i), (ii) and    (iii).-   27. The system of any one of embodiments 24 to 26, wherein the    system produces AA at about 200 to about 800 kilotons per annum    (kta).-   28. The system of any one of embodiments 24 to 27, wherein the AA is    glacial acrylic acid (GAA).-   29. The system of any one of embodiments 24 to 27, wherein the AA is    substantially free of an aldehyde impurity or a compound that    derives from the oxidation of propylene.-   30. The system of any one of embodiments 24 to 27, wherein the AA    has less than 5%, less than 4%, less than 3%, less than 2%, less    than 1%, less than 0.9%, less than 0.8%, less than 0.7%, less than    0.6%, less than 0.5%, less than 0.4%, less than 0.3%, less than    0.2%, less than 0.1%, less than 0.05%, less than 0.01%, or less than    0.001%, by weight of an aldehyde impurity or a compound that derives    from the oxidation of propylene.-   31. The system of any one of embodiments 24 to 27, wherein the AA    has less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10    ppm of an aldehyde impurity or a compound that derives from the    oxidation of propylene.-   32. The system of any one of embodiments 24 to 31, wherein the inlet    to the fourth reactor is configured to receive one or more reactant    streams comprising sodium hydroxide, and the fourth reaction zone is    configured to form a PAA sodium salt from the one or more reactant    streams in the presence of a radical initiator.-   33. The system of any one of embodiments 24 to 32, wherein the    fourth reaction zone is configured to convert at least some of the    AA to polyacrylic acid (PAA), or a salt thereof, by gel    polymerization, suspension polymerization, or solution    polymerization.-   34. The system of any one of embodiments 24 to 33, wherein the PAA,    or a salt thereof, is substantially free of an aldehyde impurity or    a compound that derives from the oxidation of propylene.-   35. The system of any one of embodiments 24 to 33, wherein the PAA    has less than 5%, less than 4%, less than 3%, less than 2%, less    than 1%, less than 0.9%, less than 0.8%, less than 0.7%, less than    0.6%, less than 0.5%, less than 0.4%, less than 0.3%, less than    0.2%, less than 0.1%, less than 0.05%, less than 0.01%, or less than    0.001%, by weight of an aldehyde impurity or a compound that derives    from the oxidation of propylene.-   36. The system of any one of embodiments 24 to 33, wherein the PAA    has less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10    ppm of an aldehyde impurity or a compound that derives from the    oxidation of propylene.-   37. The system of any one of embodiments 24 to 36, wherein the inlet    to the fourth reactor is configured to further receive one or more    reactant streams each comprising a coreactant to co-polymerize with    AA, and the fourth reaction zone is configured to form one or more    co-polymers of PAA selected from a polyacrylamide copolymer,    ethylene maleic anhydride copolymer, cross-linked    carboxymethylcellulose copolymer, polyvinyl alcohol copolymer,    cross-linked polyethylene oxide copolymer, and starch grafted    polyacrylonitrile copolymer of PAA.-   38. The system of any one of embodiments 24 to 37, further    comprising:    -   a fifth reactor, comprising:        -   an inlet configured to receive PAA, or a salt thereof, from            the PAA stream of the fourth reactor,        -   a fifth reaction zone configured to convert at least some of            the PAA, or a salt thereof, to superabsorbent polymer (SAP),            and        -   an outlet configured to provide a SAP stream comprising the            SAP.-   39. The system of embodiment 38, wherein the inlet to the fifth    reactor is configured to further receive one or more reactant    streams each comprising a cross-linking agent.-   40. The system of embodiment 38 or 39, wherein the SAP has less than    about 1000 parts per million residual monoethylenically unsaturated    monomer.-   41. The system of any one of embodiments 38 to 40, wherein the SAP    is substantially free of an aldehyde impurity or a compound that    derives from the oxidation of propylene.-   42. The system of any one of embodiments 38 to 40, wherein the SAP    has less than 5%, less than 4%, less than 3%, less than 2%, less    than 1%, less than 0.9%, less than 0.8%, less than 0.7%, less than    0.6%, less than 0.5%, less than 0.4%, less than 0.3%, less than    0.2%, less than 0.1%, less than 0.05%, less than 0.01%, or less than    0.001%, by weight of an aldehyde impurity or a compound that derives    from the oxidation of propylene.-   43. The system of any one of embodiments 38 to 40, wherein the SAP    has less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10    ppm of an aldehyde impurity or a compound that derives from the    oxidation of propylene.-   44. A method for converting ethylene to polyacrylic acid (PAA)    within an integrated system, the method comprising:    -   providing an ethylene stream comprising ethylene to an oxidative        reactor of the integrated system;    -   converting at least a portion of the ethylene in the ethylene        stream to ethylene oxide (EO) in the oxidative reactor to        produce an EO stream comprising the EO;    -   providing the EO stream from the oxidative reactor, and a carbon        monoxide (CO) stream comprising CO to a central reaction zone of        the integrated system;    -   contacting the EO stream and the CO stream with a metal carbonyl        in the central reaction zone;    -   converting at least a portion of the EO in the EO stream to beta        propiolactone (BPL) or polypropiolactone (PPL), or a combination        thereof, in the central reaction zone to produce a carbonylation        stream comprising BPL, or a carbonylation stream comprising PPL,        or a combination thereof;    -   (i) directing the carbonylation stream comprising BPL to an AA        reactor, and converting at least some of the BPL in the        carbonylation stream to AA in the AA reactor to produce an AA        stream comprising the AA; or    -   (ii) directing the carbonylation stream comprising BPL to a PPL        reactor, converting at least some of the BPL in the        carbonylation stream to PPL in the PPL reactor to produce a PPL        stream comprising PPL, directing the PPL stream to an AA reactor        (also referred to in FIG. 1 as second (b) reactor), and        converting at least some of the PPL to AA in the AA reactor to        produce an AA stream; or    -   (iii) directing the carbonylation stream comprising PPL to an AA        reactor, and converting at least some of the PPL in the        carbonylation stream to AA in the AA reactor to produce an AA        stream comprising AA; or    -   any combinations of (i)-(iii) above;    -   directing the AA streams of (i)-(iii) above to a PAA reactor;        and    -   converting at least a portion of the AA of the AA streams of        (i)-(iii) above to polyacrylic acid (PAA), or a salt thereof, in        the PAA reactor.-   45. The method of embodiment 44, comprising two of (i), (ii) and    (iii).-   46. The method of embodiment 44, comprising three of (i), (ii) and    (iii).-   47. The method of any one of embodiments 44 to 46, wherein AA is    produced at about 200 to about 800 kilotons per annum (kta).-   48. The method of any one of embodiments 44 to 47, wherein the AA is    glacial acrylic acid (GAA).-   49. The method of any one of embodiments 44 to 47, wherein the AA is    substantially free of an aldehyde impurity or a compound that    derives from the oxidation of propylene.-   50. The method of any one of embodiments 44 to 47, wherein the AA    has less than 5%, less than 4%, less than 3%, less than 2%, less    than 1%, less than 0.9%, less than 0.8%, less than 0.7%, less than    0.6%, less than 0.5%, less than 0.4%, less than 0.3%, less than    0.2%, less than 0.1%, less than 0.05%, less than 0.01%, or less than    0.001%, by weight of an aldehyde impurity or a compound that derives    from the oxidation of propylene.-   51. The method of any one of embodiments 44 to 47, wherein the AA    has less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10    ppm of an aldehyde impurity or a compound that derives from the    oxidation of propylene.-   52. The method of any one of embodiments 44 to 51, wherein the PAA    is substantially free of an aldehyde impurity or a compound that    derives from the oxidation of propylene.-   53. The method of any one of embodiments 44 to 51, wherein the PAA    has less than 5%, less than 4%, less than 3%, less than 2%, less    than 1%, less than 0.9%, less than 0.8%, less than 0.7%, less than    0.6%, less than 0.5%, less than 0.4%, less than 0.3%, less than    0.2%, less than 0.1%, less than 0.05%, less than 0.01%, or less than    0.001%, by weight of an aldehyde impurity or a compound that derives    from the oxidation of propylene.-   54. The method of any one of embodiments 44 to 51, wherein the PAA    has less than 10,000 ppm, 1,000 ppm, 500 ppm, 100 ppm, 50 ppm, 10    ppm of an aldehyde impurity or a compound that derives from the    oxidation of propylene.-   55. The method of any one of embodiments 44 to 54, further    comprising:    -   providing a PAA stream comprising the PAA, or a salt thereof,        from the PAA reactor;    -   directing the PAA stream to a superabsorbent polymer (SAP)        reactor; and    -   converting at least a portion of the PAA in the PAA stream to        SAP in the SAP reactor.-   56. The method of embodiment 55, wherein the SAP has less than about    1000 parts per million residual monoethylenically unsaturated    monomer.-   57. The method of any one of embodiments 44 to 56, wherein the AA is    converted to PAA less than one week after the ethylene is converted    to EO.-   58. The method of any one of embodiments 44 to 56, wherein the AA is    converted to PAA less than two days after the ethylene is converted    to EO.

The foregoing has been a description of certain non-limiting embodimentsof the invention. Accordingly, it is to be understood that theembodiments of the invention herein described are merely illustrative ofthe application of the principles of the invention. Reference herein todetails of the illustrated embodiments is not intended to limit thescope of the claims, which themselves recite those features regarded asessential to the invention.

What is claimed is:
 1. An integrated system for producing polyacrylicacid (PAA) and superabsorbent polymer (SAP) from ethylene, comprising:an oxidative reactor, comprising: an inlet configured to receiveethylene, an oxidative reaction zone configured to convert ethylene toethylene oxide (EO), and an outlet configured to provide an EO streamcomprising the EO; a central reactor, comprising: an inlet configured toreceive EO from the EO stream of the oxidative reactor, and carbonmonoxide (CO) from a CO source, a central reaction zone configured toconvert EO to beta propiolactone (BPL) or polypropiolactone (PPL), or acombination thereof, and an outlet configured to provide a carbonylationstream comprising the BPL, or a carbonylation stream comprising the PPL,or a combination thereof; one or more of (i), (ii) and (iii): (i) afirst reactor, comprising: an inlet configured to receive BPL from thecarbonylation stream of the central reactor, a first reaction zoneconfigured to convert BPL to acrylic acid (AA), and an outlet configuredto provide an AA stream comprising the AA, (ii) a second (a) reactor,comprising: an inlet configured to receive BPL from the carbonylationstream of the central reactor, a second (a) reaction zone configured toconvert BPL to PPL, and an outlet configured to provide a PPL streamcomprising the PPL, and a second (b) reactor, comprising: an inletconfigured to receive the PPL stream of the second (a) reactor, a second(b) reaction zone configured to convert at least some of the PPL to AA,and an outlet configured to provide an AA stream comprising the AA, and(iii) a third reactor, comprising: an inlet configured to receive PPLfrom the carbonylation stream of the central reactor, a third reactionzone configured to convert PPL to AA, and an outlet configured toprovide an AA stream comprising the AA; a fourth reactor, comprising: aninlet configured to receive the AA stream of one or more of the first,second (b) and third reactor, a fourth reaction zone configured toconvert AA to polyacrylic acid (PAA), or a salt thereof, and an outletconfigured to provide a PAA stream comprising the PAA, or a saltthereof; a fifth reactor, comprising: an inlet configured to receivePAA, or a salt thereof, from the PAA stream of the fourth reactor, afifth reaction zone configured to directly convert the PAA, or a saltthereof, to superabsorbent polymer (SAP), and an outlet configured toprovide a SAP stream comprising the SAP; and a controller toindependently modulate production of the EO, BPL, PPL, AA, PAA and SAP.2. The system of claim 1, comprising two of (i), (ii) and (iii).
 3. Thesystem of claim 1, comprising (i), (ii) and (iii).
 4. The system ofclaim 1, wherein the system produces AA at 200 kilotons to 800 kilotonsper annum (kta).
 5. The system of claim 1, wherein the AA has less than5% by weight of an aldehyde impurity or a compound that derives from theoxidation of propylene.
 6. The system of claim 1, wherein the inlet tothe fourth reactor is configured to receive one or more reactant streamscomprising sodium hydroxide, and the fourth reaction zone is configuredto form a PAA sodium salt from the one or more reactant streams in thepresence of a radical initiator.
 7. The system of claim 1, wherein thefourth reaction zone is configured to convert AA to polyacrylic acid(PAA), or a salt thereof, by gel polymerization, suspensionpolymerization, or solution polymerization.
 8. The system of claim 1,wherein the PAA, or a salt thereof, has less than 5% by weight of analdehyde impurity or a compound that derives from the oxidation ofpropylene.
 9. The system of claim 1, wherein the inlet to the fourthreactor is configured to further receive one or more reactant streamseach comprising a co-reactant to co-polymerize with AA, and the fourthreaction zone is configured to form one or more co-polymers of PAAselected from the group consisting of a polyacrylamide co-polymer,ethylene maleic anhydride co-polymer, cross-linkedcarboxymethylcellulose co-polymer, polyvinyl alcohol co-polymer,cross-linked polyethylene oxide co-polymer, and starch graftedpolyacrylonitrile co-polymer of PAA.
 10. The system of claim 1, whereinthe inlet to the fifth reactor is configured to further receive one ormore reactant streams each comprising a cross-linking agent.
 11. Thesystem of claim 1, wherein the SAP has less than 1000 parts per millionresidual monoethylenically unsaturated monomer, and has less than 5% byweight of an aldehyde impurity or a compound that derives from theoxidation of propylene.
 12. The system of claim 1, wherein thecontroller independently modulates production of the BPL by the centralreactor.
 13. The system of claim 1, wherein the AA stream has: less than1000 parts per million residual monoethylenically unsaturated monomer,(ii) less than 5% by weight or less than 10,000 ppm of an aldehydeimpurity, (iii) less than 5% by weight or less than 10,000 ppm of acompound that derives from the oxidation of propylene, (iv) less than 5%by weight or less than 10,000 ppm of furfural, (v) less than 5% byweight or less than 10,000 ppm of acetic acid, (vi) less than 5% byweight or less than 10,000 ppm of stabilizers, (vii) less than 5% byweight or less than 10,000 ppm of radical polymerization inhibitors,(viii) less than 5% by weight or less than 10,000 ppm of anti-foamagents, or any combination of (i)-(viii).